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70-433: Sender ID is heavily based on SPF , with only a few additions. Sender ID tries to improve on SPF: SPF does not verify the header addresses (of which there can be more than one) that indicate the claimed sending party. One of these header addresses is typically displayed to the user and may be used to reply to emails. These header addresses can be different from the address that SPF tries to verify; that is, SPF verifies only

140-456: A "message/rfc822" or a "text/rfc822-headers". Forensic Reports also contain the following: There are several different types of email forwarding , some of which may break SPF. This is one of the reasons why email forwarding can affect DMARC authentication results. Mailing lists are a frequent cause of legitimate breakage of the original author's domain DKIM signature, for example by adding

210-675: A PERMERROR. Another safeguard is the maximum of ten mechanisms querying DNS, i.e. any mechanism except from IP4, IP6, and ALL. Implementations can abort the evaluation with result TEMPERROR when it takes too long or a DNS query times out or they can continue pretending that the query returned no data —which is called a "void lookup". However, they must return PERMERROR if the policy directly or indirectly needs more than ten queries for mechanisms . In addition, they should return PERMERROR as soon as more than two "void lookups" have been encountered. Any redirect= also counts towards this processing limits . A typical SPF HELO policy v=spf1

280-577: A SOFTFAIL policy) until they are satisfied with the results. See below for a list of alternatives to plain message forwarding. For an empty Return-Path as used in error messages and other auto-replies, an SPF check of the HELO identity is mandatory. With a bogus HELO identity the result NONE would not help, but for valid host names SPF also protects the HELO identity. This SPF feature was always supported as an option for receivers, and later SPF drafts including

350-427: A comma. Target email addresses can belong to external domains. In that case, the target domain has to set up a DMARC record to say it agrees to receive them, otherwise it would be possible to exploit reporting for spam amplification . For example, say receiver.example receives a mail message From: someone@sender.example and wishes to report it. If it finds ruf=mailto:some-id@thirdparty.example , it looks for

420-475: A confirming DNS record in the namespace administered by the target, like this: Aggregate Reports are sent as XML files, typically once per day. The subject mentions the "Report Domain", which indicates the DNS domain name about which the report was generated, and the "Submitter", which is the entity issuing the report. The payload is in an attachment with a long filename consisting of bang-separated elements such as

490-446: A domain publishes an SPF FAIL policy, legitimate messages sent to receivers forwarding their mail to third parties may be rejected and/or bounced if all of the following occur: This is a necessary and obvious feature of SPF – checks behind the "border" MTA ( MX ) of the receiver cannot work directly. Publishers of SPF FAIL policies must accept the risk of their legitimate emails being rejected or bounced. They should test (e.g., with

560-566: A domain with a sender policy, or abuse a compromised system in this domain. However, doing so makes the spammer easier to trace. The main benefit of SPF is to the owners of email addresses that are forged in the Return-Path. They receive large numbers of unsolicited error messages and other auto-replies. If such receivers use SPF to specify their legitimate source IP addresses and indicate FAIL result for all other addresses, receivers checking SPF can reject forgeries, thus reducing or eliminating

630-539: A first attempt at an SPF-like specification was published in 2002 on the IETF "namedroppers" mailing list by Dana Valerie Reese, who was unaware of the 2000 mention of the idea. The very next day, Paul Vixie posted his own SPF-like specification on the same list. These posts ignited a lot of interest, led to the forming of the IETF Anti-Spam Research Group (ASRG) and their mailing list, where

700-402: A forwarder and a mailing list, respectively. DMARC authentication failed for the last row only; it could have affected the message disposition if example.org had specified a strict policy. The disposition reflects the policy published actually applied to the messages, none , quarantine , or reject . Along with it, not shown in the table, DMARC provides for a policy override. Some reasons why

770-510: A mailing list, and then the list operator is forced to reject it or do From: rewriting. One of the most popular and least intrusive workarounds consists of rewriting the From: header field. The original author's address can then be added to the Reply-To: field. Rewriting can range from just appending .INVALID to the domain name, to allocating a temporary user ID where a modified version of

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840-438: A message can fail even if it passes SPF or DKIM but fails alignment. Setting up DMARC may improve the deliverability of messages from legitimate senders. DMARC operates by checking that the domain in the message's From: field (also called "RFC5322.From" ) is "aligned" with other authenticated domain names. If either SPF (specified using the aspf field) or DKIM (specified using the adkim ) alignment checks pass, then

910-423: A mx ip4:192.0.2.0 -all may execute four or more DNS queries: (1) TXT record (SPF type was obsoleted by RFC 7208), (2) A or AAAA for mechanism a , (3) MX record and (4+) A or AAAA for each MX name, for mechanism mx . Except the first one, all those queries count towards the limit of 10. In addition if, for example, the sender has an IPv6 address, while its name and its two MX names have only IPv4 addresses, then

980-559: A number of records. Records can be put in a database as a relation and viewed in a tabular form. The XML schema is defined in Appendix C of specifications and a raw record is exemplified in dmarc.org. Here we stick with a relational example, which better conveys the nature of the data. DMARC records can also be directly transformed in HTML by applying an XSL stylesheet . Rows are grouped by source IP and authentication results, passing just

1050-502: A prefix to the subject header. A number of workarounds are possible, and mailing list software packages are working on solutions. This workaround keeps the standard mailing list workflow, and is adopted by several large mailing list operators, but precludes the list adding footers and subject prefixes. This requires careful configuration of mailing software to make sure signed headers are not reordered or modified. A misconfigured email server may put List-id in its DKIM of messages sent to

1120-443: A receiver can apply a policy different from the one requested are already provided for by the specification: Forensic Reports, also known as Failure Reports, are generated in real time and consist of redacted copies of individual messages that failed SPF, DKIM or both based upon what value is specified in the fo tag. Their format, an extension of Abuse Reporting Format , resembles that of regular bounces in that they contain either

1190-504: A significant amount of disruption, and those mailbox providers have been accused of forcing the costs of their own security failures onto third parties. As of 2020, the FAQ in the official DMARC wiki contains several suggestions for mailing lists to handle messages from a domain with a strict DMARC policy, of which the most widely implemented is the mailing list changing the “From” header to an address in its own domain. An IETF working group

1260-506: A specific Resource Record type 99 to SPF the uptake of was never high, and having two mechanisms was confusing for users. In 2014 the use of this record was discontinued after the SPFbis working group concluded that " ...significant migration to the SPF RR type in the foreseeable future was very unlikely and that the best solution for resolving this interoperability issue was to drop support for

1330-528: A survey published in 2007, 5% of the .com and .net domains had some kind of SPF policy. In 2009, a continuous survey run at Nokia Research reports that 51% of the tested domains specify an SPF policy. These results can include trivial policies like v=spf1 ?all . In April 2007, BITS, a division of the Financial Services Roundtable, published email security recommendations for its members including SPF deployment. In 2008,

1400-586: Is called 'identifier alignment'. Custom proprietary implementations are required to protect against such display name spoofing and cannot utilize SPF. Anti-spam software such as SpamAssassin version 3.0.0 and ASSP implement SPF. Many mail transfer agents (MTAs) support SPF directly such as Courier , CommuniGate Pro, Wildcat , MDaemon, and Microsoft Exchange , or have patches or plug-ins available that support SPF, including Postfix , Sendmail , Exim , qmail , and Qpsmtpd . As of 2017, more than eight million domains publish SPF FAIL -all policies. In

1470-464: Is covered by the preceding change in the From: header field. That way, the original meaning of those fields is reversed. Altering the author is not fair in general, and can break the expected relationship between meaning and appearance of that datum. It also breaks automated use of it. There are communities which use mailing lists to coordinate their work, and deploy tools which use the From: field to attribute authorship to attachments. Wrapping

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1540-415: Is exploited by spammers and scammers who often use forged email addresses , making it more difficult to trace a message back to its source, and easy for spammers to hide their identity in order to avoid responsibility. It is also used in phishing techniques, where users can be duped into disclosing private information in response to an email purportedly sent by an organization such as a bank. SPF allows

1610-517: Is known as email spoofing , and is often used in phishing and email spam . The list of authorized sending hosts and IP addresses for a domain is published in the DNS records for that domain. Sender Policy Framework is defined in RFC 7208 dated April 2014 as a "proposed standard". The first public mention of the concept was in 2000 but went mostly unnoticed. No mention was made of the concept again until

1680-506: Is replaced with one of: The only other syntactical difference is that Sender ID offers the feature of positional modifiers not supported in SPF. In practice, so far no positional modifier has been specified in any Sender ID implementation. In practice, the pra scheme usually only offers protection when the email is legitimate, while offering no real protection in the case of spam or phishing. The pra for most legitimate email will be either

1750-472: Is to protect a domain from being used in business email compromise attacks , phishing email, email scams and other cyber threat activities. Once the DMARC DNS entry is published, any receiving email server can authenticate the incoming email based on the instructions published by the domain owner within the DNS entry. If the email passes the authentication, it will be delivered and can be trusted. If

1820-538: The Open Specification Promise , which is compatible with some free and open source licenses, but not with the most recent version of the GPL license, version 3.x. Sender Policy Framework Sender Policy Framework ( SPF ) is an email authentication method which ensures the sending mail server is authorized to originate mail from the email sender's domain. This authentication only applies to

1890-535: The pra , compared to some 40~50% of mail domains using SPF. The Sender ID proposal was the subject of controversy regarding licensing issues: Microsoft holds patents on key parts of Sender ID and used to license those patents under terms that were not compatible with the GNU General Public License and which were considered problematic for free software implementations in general. On October 23, 2006, Microsoft placed those patents under

1960-414: The "MAIL FROM" address, also called the envelope sender. However, there are many similar email header fields that all contain sending party information; therefore Sender ID defines in RFC 4407 a Purported Responsible Address (PRA) as well as a set of heuristic rules to establish this address from the many typical headers in an email. Syntactically, Sender ID is almost identical to SPF except that v=spf1

2030-498: The DMARC alignment test passes. Alignment may be specified as strict or relaxed. For strict alignment, the domain names must be identical. For relaxed alignment, the top-level "Organizational Domain" must match. The Organizational Domain used to be found by checking a list of public DNS suffixes. The upcoming spec instead specifies a Tree Walk through the parent domains. So, for example, "a.b.c.d.example.com.au" and "example.com.au" have

2100-586: The IP address of the sending server is authorized by the owner of the domain that appears in the SMTP MAIL FROM command. (The email address in MAIL FROM is also called the bounce address , envelope-from or RFC5321.MailFrom.) In addition to requiring that the SPF check passes, DMARC checks that RFC5321.MailFrom aligns with 5322.From. DKIM allows parts of an email message to be cryptographically signed, and

2170-572: The MAAWG stated: "Authentication supports transparency by further identifying the sender(s) of a message, while also contributing to the reduction or elimination of spoofed and forged addresses". DMARC Domain-based Message Authentication, Reporting and Conformance ( DMARC ) is an email authentication protocol. It is designed to give email domain owners the ability to protect their domain from unauthorized use, commonly known as email spoofing . The purpose and primary outcome of implementing DMARC

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2240-425: The MAIL FROM. The most problematic point in the core Sender ID specification is its recommendation to interpret v=spf1 policies like spf2.0/mfrom,pra instead of spf2.0/mfrom . This was never intended by all published SPF drafts since 2003, and for an unknown large number of v=spf1 policies an evaluation for pra could cause bogus results for many cases where pra and mfrom are different. This problem

2310-634: The Messaging Anti-Abuse Working Group (MAAWG) published a paper about email authentication covering SPF, Sender ID , and DomainKeys Identified Mail (DKIM). In their "Sender Best Communication Practices" the MAAWG stated: "At the very least, senders should incorporate SPF records for their mailing domains". In 2015, the Messaging Anti-Abuse Working Group (MAAWG) revised a paper about email authentication covering SPF, DomainKeys Identified Mail (DKIM), and DMARC (DMARC). In their revised "Sender Best Communication Practices"

2380-468: The SPF RR type." As SPF increasingly prevents spammers from spoofing the envelope-from address, many have moved to only spoof the address in the From field of the mail header, which is actually displayed to the recipient rather than only processed by the recipient's message transfer agent (MTA). SPF (or DKIM ) can be used together with DMARC though, to also check the From field of the mail header. This

2450-554: The SPF idea was further developed. Among the proposals submitted to the ASRG were "Reverse MX " (RMX) by Hadmut Danisch, and "Designated Mailer Protocol" (DMP) by Gordon Fecyk. In June 2003, Meng Weng Wong merged the RMX and DMP specifications and solicited suggestions from others. Over the next six months, a large number of changes were made and a large community had started working on SPF. Originally SPF stood for Sender Permitted From and

2520-475: The amount of backscatter . SPF has potential advantages beyond helping identify unwanted mail. In particular, if a sender provides SPF information, then receivers can use SPF PASS results in combination with an allow list to identify known reliable senders. Scenarios like compromised systems and shared sending mailers limit this use. If a domain publishes an SPF record, spammers and phishers are less likely to forge emails pretending to be from that domain, because

2590-466: The author(s) of the message, that is, the mailbox(es) of the person(s) or system(s) responsible for the writing of the message." Mailbox refers to the author's email address. The Sender: header is available to indicate that an email was sent on behalf of another party, but DMARC only checks policy for the From domain and ignores the Sender domain. Both ADSP and DMARC reject using the Sender field on

2660-605: The authority delegation scheme of the Domain Name System. Current practice requires the use of TXT records, just as early implementations did. For a while a new record type (SPF, type 99) was registered and made available in common DNS software. Use of TXT records for SPF was intended as a transitional mechanism at the time. The experimental RFC, RFC 4408, section 3.1.1, suggested "an SPF-compliant domain name SHOULD have SPF records of both RR types". The proposed standard, RFC 7208, says "use of alternative DNS RR types

2730-432: The count of each group. The leftmost result columns, labelled SPF and DKIM show DMARC-wise results, either pass or fail, taking alignment into account. The rightmost ones, with similar labels, show the name of the domain which claims to participate in the sending of the message and (in parentheses) the authentication status of that claim according to the original protocol, SPF or DKIM, regardless of Identifier Alignment. On

2800-530: The domain in the d= tag aligns with the sender's domain stated in the From: header field. DMARC records are published in DNS with a subdomain label _dmarc , for example _dmarc.example.com . Compare this to SPF at example.com , and DKIM at selector._domainkey.example.com . The content of the TXT resource record consists of name=value tags, separated by semicolons, similar to SPF and DKIM. The available tags are: For example: In this example,

2870-506: The domain, and subsequently also accepts the recipients and the body of the message, it should insert a Return-Path field in the message header in order to save the envelope-from address. While the address in the Return-Path often matches other originator addresses in the mail header such as the header-from , this is not necessarily the case, and SPF does not prevent forgery of these other addresses such as sender header. Spammers can send email with an SPF PASS result if they have an account in

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2940-437: The email fails the check, depending on the instructions held within the DMARC record the email could be delivered, quarantined or rejected. DMARC extends two existing email authentication mechanisms, Sender Policy Framework (SPF) and DomainKeys Identified Mail (DKIM). It allows the administrative owner of a domain to publish a policy in their DNS records to specify how to check the From: field presented to end users; how

3010-399: The email sender listed in the "envelope from" field during the initial SMTP connection. If the email is bounced, a message is sent to this address, and for downstream transmission it typically appears in the "Return-Path" header. To authenticate the email address which is actually visible to recipients on the "From:" line, other technologies such as DMARC must be used. Forgery of this address

3080-457: The entity controlling the example.com DNS domain intends to monitor SPF and/or DKIM failure rates and doesn't expect email to be sent from subdomains of example.com. Note that a subdomain can publish its own DMARC record; receivers must check it out before falling back to the organizational domain record. The protocol provides for various ratchets, or transitional states, to allow mail admins to gradually transition from not implementing DMARC at all

3150-552: The evaluation of the first two mechanisms already results in more than two void lookups and hence PERMERROR. Mechanisms ip4 , ip6 and all need no DNS lookup. To enable rapid testing and deployment, initial versions of SPF checked for its setting in the DNS TXT record of the sending domain - even though this record was traditionally supposed to be free-form text with no semantics attached. Although in July 2005, IANA assigned

3220-606: The familiar From: header field, or, in the case of mailing lists, the Sender: header field. In the case of phishing or spam, however, the pra may be based on Resent-* header fields that are often not displayed to the user. To be an effective anti-phishing tool, the MUA (Mail User Agent or Mail Client) will need to be modified to display either the pra for Sender ID, or the Return-Path: header field for SPF. The pra tries to counter

3290-403: The final specification recommend to check the HELO always. This allows receivers to allowlist sending mailers based on a HELO PASS, or to reject all mails after a HELO FAIL. It can also be used in reputation systems (any allow or deny list is a simple case of a reputation system). Compliance with SPF consists of three loosely related tasks: Thus, the key issue in SPF is the specification for

3360-427: The forged emails are more likely to be caught in spam filters which check the SPF record. Therefore, an SPF-protected domain is less attractive to spammers and phishers. Because an SPF-protected domain is less attractive as a spoofed address, it is less likely to be denylisted by spam filters and so ultimately the legitimate email from the domain is more likely to get through. SPF breaks plain message forwarding . When

3430-459: The given percentage of messages by a simple Bernoulli sampling algorithm. The rest of the messages should undergo the lower policy; that is, none if p=quarantine , quarantine if p=reject . If not specified, pct defaults to 100% of messages. The case p=quarantine; pct=0; is being used to force mailing list managers to rewrite the From: field, as some don't do so when p=none . Finally,

3500-401: The mail header, e.g. by inserting a Sender or Resent-Sender . The latter violates RFC 2822 and can be incompatible with RFC 822. With SPF, mailing lists continue to work as is. Forwarders wishing to support SPF only need to modify SMTP MAIL FROM and RCPT TO, not the mail. This concept is not new: with the original RFC 821 SMTP forwarders always added their host name to the reverse path in

3570-537: The message or quarantine it. The policy can also specify how an email receiver can report back to the sender's domain about messages that pass and/or fail. These policies are published in the public Domain Name System (DNS) as text TXT records . DMARC does not directly address whether or not an email is spam or otherwise fraudulent. Instead, DMARC can require that a message not only pass DKIM or SPF validation, but that it also pass § Alignment . Under DMARC

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3640-539: The message should be rejected. Eight mechanisms are defined: Each mechanism can be combined with one of four qualifiers : The modifiers allow for future extensions to the framework. To date only the two modifiers defined in the RFC 4408 have been widely deployed: As soon as SPF implementations detect syntax errors in a sender policy they must abort the evaluation with result PERMERROR. Skipping erroneous mechanisms cannot work as expected, therefore include:bad.example and redirect=bad.example also cause

3710-482: The message works nicely, for those who use an email client which understands wrapped messages. Not doing any change is perhaps the most obvious solution, except that they seem to be legally required in some countries, and that routinely losing SPF authentication may render overall authentication more fragile. Making changes to the From: header field to pass DKIM alignment may bring the message out of compliance with RFC 5322 section 3.6.2: "The 'From:' field specifies

3780-435: The new DNS information that domains set and receivers use. The records laid out below are in typical DNS syntax, for example: "v=" defines the version of SPF used. The following words provide mechanisms to use to determine if a domain is eligible to send mail. The "ip4" and "a" specify the systems permitted to send messages for the given domain. The "-all" at the end specifies that, if the previous mechanisms did not match,

3850-703: The non-technical basis that many user agents do not display this to the recipient. A draft DMARC specification has been maintained since 30 January 2012. In October 2013, GNU Mailman 2.1.16 was released with options to handle posters from a domain with the DMARC policy of p=reject . The change tried to anticipate the interoperability issues expected in case restrictive policies were applied to domains with human users (as opposed to purely transactional mail domains). In April 2014, Yahoo changed its DMARC policy to p=reject , thereby causing misbehavior in several mailing lists. A few days later, AOL also changed its DMARC policy to p=reject . Those moves resulted in

3920-483: The owner of an Internet domain to specify which computers are authorized to send mail with envelope-from addresses in that domain, using Domain Name System (DNS) records. Receivers verifying the SPF information in TXT records may reject messages from unauthorized sources before receiving the body of the message. Thus, the principles of operation are similar to those of DNS-based blackhole lists ( DNSBL ), except that SPF uses

3990-426: The problem of phishing , while SPF or mfrom tries to counter the problem of spam bounces and other auto-replies to forged Return-Paths. Two different problems with two different proposed solutions. However, Sender-ID and SPF yield the same result in approximately 80% of the cases, according to a billion message analysis. The pra has the disadvantage that forwarders and mailing lists can only support it by modifying

4060-554: The receiver should deal with failures – and provides a reporting mechanism for actions performed under those policies. DMARC is defined in the Internet Engineering Task Force 's published document RFC 7489 , dated March 2015, as "Informational". A DMARC policy allows a sender's domain to indicate that their email messages are protected by SPF and/or DKIM, and tells a receiver what to do if neither of those authentication methods passes – such as to reject

4130-414: The report-issuing receiver, the begin and end epochs of the reported period as Unix-style time stamps, an optional unique identifier and an extension which depends on the possible compression (used to be .zip ). For example: example.com!example.org!1475712000!1475798400.xml.gz . The XML content consists of a header, containing the policy on which the report is based and report metadata, followed by

4200-518: The right side, SPF can appear at most twice, once for the Return-Path: test and once for the HELO test; DKIM can appear once for each signature present in the message. In the example, the first row represents the main mail flow from example.org, and the second row is a DKIM glitch, such as signature breakage due to a minor alteration in transit. The third and fourth rows show typical failures modes of

4270-500: The same Organizational Domain, because _dmarc.example.com.au is the only defined DMARC record among all the subdomains involved, including _dmarc.au. As this allows domain owners to define domain roles, it is deemed to be more accurate than the Public Suffix List . Like SPF and DKIM, DMARC uses the concept of a domain owner, the entity or entities that are authorized to make changes to a given DNS domain. SPF checks that

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4340-494: The signature must cover the From field. Within the DKIM-Signature mail header, the d= (domain) and s= (selector) tags specify where in DNS to retrieve the public key for the signature. A valid signature proves that the signer is a domain owner, and that the From field hasn't been modified since the signature was applied. There may be several DKIM signatures on an email message; DMARC requires one valid signature where

4410-523: The specification was approved by the IESG as an IETF experiment , inviting the community to observe SPF during the two years following publication. On April 28, 2006, the SPF RFC was published as experimental RFC 4408. In April 2014 IETF published SPF in RFC 7208 as a "proposed standard". The Simple Mail Transfer Protocol permits any computer to send email claiming to be from any source address. This

4480-572: The subdomain policy, sp= and the newly added no-domain policy, np= allow tweaking the policy for specific subdomains. DMARC is capable of producing two separate types of reports. Aggregate reports are sent to the address specified following the rua . Forensic reports are emailed to the address following the ruf tag. These mail addresses must be specified in URI mailto format (e.g. mailto:worker@example.net ). Multiple reporting addresses are valid and must each be in full URI format, separated by

4550-444: The user's address is used, or an opaque ID is used, which keeps the user's "real" email address private from the list. In addition, the display name can be changed so as to show both the author and the list (or list operator). Those examples would result, respectively, in one of the following: The last line, Reply-To: , has to be designed in order to accommodate reply-to-author functionality, in which case reply-to-list functionality

4620-436: The way through to an unyielding setup. The concept of stepwise adoption assumes that the goal of DMARC is the strongest setting, which is not the case for all domains. Regardless of intent, these mechanisms allow for greater flexibility. First and foremost, there are three policies: The policy published can be mitigated by applying it to only a percentage of the messages that fail DMARC check. Receivers are asked to select

4690-621: Was formed in August 2014 in order to address DMARC issues, starting from interoperability concerns and possibly continuing with a revised standard specification and documentation. Meanwhile, the existing DMARC specification had reached an editorial state agreed upon and implemented by many. It was published in March 2015 on the Independent Submission stream in the "Informational" (non-standard) category as RFC 7489 . In March 2017,

4760-597: Was sometimes also called SMTP+SPF ; but its name was changed to Sender Policy Framework in February 2004. In early 2004, the IETF created the MARID working group and tried to use SPF and Microsoft's CallerID proposal as the basis for what is now known as Sender ID ; but this collapsed due to technical and licensing conflicts. The SPF community returned to the original "classic" version of SPF. In July 2005, this version of

4830-462: Was supported in SPF's experimental phase but has been discontinued". The envelope-from address is transmitted at the beginning of the SMTP dialog. If the server rejects the domain, the unauthorized client should receive a rejection message, and if that client was a relaying message transfer agent (MTA), a bounce message to the original envelope-from address may be generated. If the server accepts

4900-508: Was the basis of an appeal to the Internet Architecture Board (IAB) . In response to another prior appeal the IESG already noted that Sender ID cannot advance on the IETF standards track without addressing the incompatibility with a MUST in RFC 2822. Various surveys performed in 2012, when SPF turned from experimental to proposed standard, showed that fewer than 3% of mail domains published specific requests for using

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