spf, dkim, dmarc best practices

Since SPF delegation is valid only for a single domain, it is critical to also publish deny all SPF records for any subdomains you may be using that might not generate an email. When you set up DMARC, you can then optionally set up BIMI to add your brand logo to messages sent from your domain. , After identification, the sending server communicates the RFC5321.MailFrom address by sending the command MAIL FROM. The Sender Policy Framework is an email authentication protocol that restricts who can send emails on your domains behalf. WebSPF vs DKIM. When an email is sent to a mailing list, it is redistributed to all of its recipients. DMARC Terminology DMARC-SPF Results DMARC-DKIM Results DMARC Passing Criteria DMARC Actions Using Trend Micro Email Security DMARC To use the DMARC protection, enable the feature on the web console and configure the actions that Trend Micro Email Security will take when the DMARC violation happens. However, most Mail User Agents in use today will correctly form a new message and include the forwarded message either inline or as an attachment to the new. DKIM combines a public DNS record with a private key thats handled by your email server. Just make sure that you list any and all domains (and subdomains) you sign for in Profile Users section. It stands for DKIM alignment mode. Even if your production domain has a regular SPF record, do make an extra effort to add deny all records to your subdomains with no traffic. Delta, on the other hand, employs a different SPF scheme: delta.com text = "v=spf1 a:smtp.hosts.delta.com include:_spf.vendor.delta.com -all". SPF doesn't use an encryption algorithm, while DKIM uses an encryption algorithm It will make tracking the messages easier, and will allow for much cleaner implementation of DMARC later on. Recommended filter actions are to drop messages that Fail (-all in the SPF record), and quarantine messages that Softfail (~all in the SPF record) in a Policy Quarantine, however, this might vary according to your security requirements. DKIM combines a public DNS record with a private key thats handled by your email server. The ~all qualifier at the end instructs receivers to consider any other sources as Soft Fail one of two failure modes of SPF. Some organizations use DKIM keys they created several years ago, which isnt a good idea. In the Default Policy Parameters of Mail Flow Policies, simply turn DKIM Verification to On. Implement SPF Alignment: To enhance email authentication, consider implementing SPF alignment in conjunction with DKIM and DMARC. This guide describes three predominant email authentication technologies in use today - SPF, DKIM, and DMARC, and discusses various aspects of their implementation. , A DMARC monitoring service keeps track of a domain's outbound email channel. The authenticating domain must be the same domain that's in the message From: header. Implementing SPF, DKIM, and DMARC according to the best practices above will result in an optimal configuration that prevents third parties from spoofing your domain while simultaneously building the best possible reputation and guaranteeing legit emails reach their destination. Here are some of the best practices that you need to know to employ while using DKIM protocol: Key Length: The key length is an important attribute to pay attention to while configuring the DKIM. DMARC If all this is a bit over your head, dont worry. Best Practice for Email Authentication - Optimal Ways marketing emails) to a third-party, you dont want them to use the same keys that you use in production. Because the email was very simple to use and manage, and completely open from security and access point of view, organizations historically didnt enforce strict policies around who and how can use it. SPF DMARC Here are some best practices that you should follow when sending emails to Gmail accounts in order to avoid deliverability If you are still in the early stages of DMARC implementation, start with a p=none policy and use URIports to monitor your email traffic through DMARC reports. DKIM combines a public DNS record with a private key thats handled by your email server. Publish the key as generated in your DNS. SPF identifies IP addresses in order to determine which senders are permitted to send mail to a domain. Organizations should follow the regular DMARC enforcement route. SPF They also include instructions to Hard Fail any messages not authenticated by SPF (-all qualifier). 2:30 minute read. Here are some of the best practices that you need to know to employ while using DKIM protocol: Key Length: The key length is an important attribute to pay attention to while configuring the DKIM. Basically, SPF, along with DKIM, DMARC, and other technologies supported by Office 365, help prevent spoofing and phishing. It directs the receiver to report, quarantine, or reject emails that fail authentication checks. [1] Canonicalization is beyond the scope of this document. Gmail SPF uses TXT type DNS Resource Records of fairly simple syntax: spirit.com text = "v=spf1 mx a ip4:38.103.84.0/24 a:mx3.spirit.com a:mx4.spirit.com include:spf.protection.outlook.com ~all". Best Practices Also, if you provide some email services for a third-party domain, you will most probably need to get the key to use from them (and import it into your ESA). DMARC, DKIM, and SPF are three email authentication methods. Instead, you should generate a new key pair, publish the public portion in your DNS zone and deliver the secret key to the other party. Also read the industry best practices document I linked. DMARC or Domain-based Message Authentication, Reporting & Conformance is an email authentication standard that leverages SPF and DKIM while adding an extra layer of protection. To add DMARC please read these articles. Microsoft 365 Defender. This is why, in general, best practice for messages failing DKIM would still be to quarantine or tag, rather than drop them. For an email to pass the DMARC (Domain-based Message Authentication Reporting and Conformance), it needs to either pass and align SPF (Sender Policy Framework) or pass and align DKIM (DomainKeys Identified Mail). The DMARC p tag addresses the DMARC policy mode. Optionally, you can create DKIM Verification Profiles, and assign different Verification Profiles to different Mail Flow Policies. Similarly to the previous paragraph, if you are using any third-party emailing services, and wish to establish fully SPF-verified mail flow, you must include their own SPF records in yours. Identify which messages sent from your organization pass or fail authentication checks (SPF or DKIM, or both). View with Adobe Reader on a variety of devices, View in various apps on iPhone, iPad, Android, Sony Reader, or Windows Phone, View on Kindle device or Kindle app on multiple devices, Domain-based Message Authentication, Reporting And Conformance (DMARC), If You Provide Email Services For Other Domains Or Third-Parties, Sample Action Plan To Implement Email Authentication, https://otalliance.org/resources/spf-dmarc-record-validator, http://www.kitterman.com/dmarc/assistant.html, http://www.kitterman.com/spf/validate.html, https://www.ciscolive.com/online/connect/sessionDetail.ww?SESSION_ID=76627, https://www.m3aawg.org/sites/maawg/files/news/M3AAWG_Senders_BCP_Ver3-2015-02.pdf, Making sure that all available identities (HELO, MAIL FROM and/or DKIM signing domain) are aligned (exactly matching or subordinate) with From header, Providing a means for the sender domain owner to specify a policy for receivers on how they, Providing a feedback facility for sender domain owners to be informed of any failing messages thus making it easy to identify phishing campaigns or errors in SPF/DKIM/DMARC policy assignment, Use a single Signing Profile to sign for all domains. Organizations should follow the regular DMARC enforcement route. SPF allows email senders to define which IP addresses can send mail, while DKIM uses an encryption key and digital signature to verify an email. This domain name can differ from the RFC5321.MailFrom domain name. Dont use a single key for all your clientsensure each client has a unique key. Domain-based Message Authentication, Reporting, and Conformance ( DMARC) works with Sender Policy Framework (SPF) and DomainKeys Identified Mail (DKIM) to authenticate mail senders. Identify unauthorized sources that send email appearing to come from your organization. . Implement SPF Alignment: To enhance email authentication, consider implementing SPF alignment in conjunction with DKIM and DMARC. WebCopy article link What are DMARC, DKIM, and SPF? DKIM uses cryptographic authentication. Even if SPF is correctly deployed on the production domain, bad actors can still use other domains that are not actively used for an email to spoof an organizations identity. This guide describes three predominant email authentication technologies in use today - SPF, DKIM, and DMARC, and discusses various aspects of their implementation. As we can see, Sun Country has some of their emails under their own control, but their marketing email is outsourced to a third-party. DMARC ensures the destination email systems trust messages sent from your domain. The documentation set for this product strives to use bias-free language. You should be upping spam scores of SPF failures unless it meets two of the scenarios I mentioned in my other comment. For more details on fail and softfail, please read chapter 8.4 of the SPF RFC and chapter 10.1 of the DMARC RFC. 2023 Cisco and/or its affiliates. Make sure you have a process in place for an operator to monitor these addresses and modify SPF, DKIM and DMARC configuration appropriately, or alert the security team in case of a spoofing campaign. Best Practices: Email Authentication SPF, DKIM With EasyDMARCs reporting tools like our DMARC Aggregate XML Reports Analyzer, you can quickly parse your DMARC reports in easily understandable language to identify and resolve issues efficiently, as well as: This can increase your senders reputation and increase your deliverability rate, so your messages can always land in your receivers inbox. According to specification, a receiver must adhere to the advertised policy. Use email authentication ideally all three of DKIM, DMARC, and SPF. As an example, consider these five DKIM-Signature headers from multiple messages from Lufthansa: DKIM-Signature: v=1; a=rsa-sha1; c=relaxed/relaxed; s=lufthansa; d=newsletter.milesandmore.com; DKIM-Signature: v=1; a=rsa-sha1; c=relaxed/relaxed; s=lufthansa2; d=newsletter.lufthansa.com; DKIM-Signature: v=1; a=rsa-sha1; c=relaxed/relaxed; s=lufthansa3; d=lh.lufthansa.com; DKIM-Signature: v=1; a=rsa-sha1; c=relaxed/relaxed; s=lufthansa4; d=e.milesandmore.com. SPF and DMARC are simple DNS records. WebDMARC standardizes how email receivers perform email authentication using the well-known SPF and DKIM mechanisms. events, limited time promotions, product launches), where emails incoming to those domains would be delivered to your production domain, and any responses to those emails will be delivered from the production domain. Regarding timelines, here is a very rough outline of individual steps for a typical project. So, emails from senders @delta.com may legitimately come from, for example, Air Frances email gateways. WebDMARC standardizes how email receivers perform email authentication using the well-known SPF and DKIM mechanisms. DMARC, DKIM, and SPF are three email authentication methods. If you have your own or use a third-party marketing mail solution, you should use separate infrastructure than production email gateways. Another improvement of DMARC over previous email authentication technologies is how it handles subdomains. WebSPF vs DKIM. For the successful subsequent implementation of DMARC, you should: Properly implementing SPF will probably be the most time-consuming and cumbersome part of any email authentication infrastructure implementation. SPF Best Practices; Dont Overcrowd the SPF Record; Dont Use the +all Mechanism; DKIM Best Practices; Make DKIM Keys at Least 1024 Bits Long; Rotate your DKIM Keys Regularly; DMARC Best Practices; Get the Most Out of DMARC Reporting; Pay Attention to DMARC Alignment; Go Through DMARC Enforcement Gradually; Dont RFC7489 Domain-based Message Authentication, Reporting, and Conformance SPF verification is configured in Mail Flow Policies the easiest way to run it globally is to turn it on in the Default Policy Parameters section of the appropriate listener(s). Terminology DMARC-SPF Results DMARC-DKIM Results DMARC Passing Criteria DMARC Actions Using Trend Micro Email Security DMARC To use the DMARC protection, enable the feature on the web console and configure the actions that Trend Micro Email Security will take when the DMARC violation happens. WebCopy article link What are DMARC, DKIM, and SPF? You can also use our DMARC Record Lookup tool to check whether your domain has any DMARC records. DMARC DMARC Due to historic openness of SMTP and email and the reluctance of overall Internet to adapt to (positive) changes, there are still several situations when DKIM signatures might legitimately fail such as when mailing list managers directly relay but modify messages, or when messages are forwarded directly rather than as attachments to new messages. if only five machines in a /24 network send SMTP, add those five individual IP addresses to your SPF, rather than the entire network. , To reduce the risk of active keys being compromised, either by attackers cracking or stealing, rotating DKIM keys once every 6 months is recommended. Use email authentication ideally all three of DKIM, DMARC, and SPF. What are the best practices for SPF Management? [5] This behavior takes advantage of the fact that originally, DKIM does not verify the message source as stated in MAIL FROM or Header From at all. If an email cannot be delivered, this address is used for the non-delivery report. Freddie Leeman Jan 10, 2023 3 min read The internet is evolving, and so are email security best practices. SPF identifies IP addresses in order to determine which senders are permitted to send mail to a domain. Best Practices , The RFC5322.From address (also referred to as the Header From: address) is part of the email message itself and is usually the address that is shown in email clients to the end user. The authenticating domain must be the same domain that's in the message From: header. Optional. For a message to pass DKIM Verification, any signatures need to verify. The easiest way to do this is for the provider to create an umbrella SPF record, and have customers use include mechanism in their SPF records. However, such reports come in XML format, so theyre hard to understand and analyze. RFC7208 Sender Policy Framework M3AAWG Email Authentication Recommended Best Practices Create email aliases that will receive reports, or create a Web application that can ingest them. This is one of the main reasons for the existence of Selectors in DKIM. WebThe DKIM signature enables domain authentication to validate that the message was legitimately sent from the specified domain. This means that senders will experience consistent authentication results for their messages at AOL, Gmail, Hotmail, Yahoo! that provide insights into your email channel and the sources sending messages on your domains behalf. While some results (and formal implementation of DMARC) may be obtained by publishing an incomplete set of records and a policy of none, it is in the best interest of both the sender organization and the Internet as a whole that everyone implements it to the full extent of its capabilities. Each key pair would be referenced by a selector so DKIM verifiers can differentiate between keys. In that case, you have two options: Although option #1is easier to start with, remember that it will ultimately break DMARC. So we advise against it. suncountry.com text = "v=spf1 mx ip4:207.238.249.242 ip4:146.88.177.148 ip4:146.88.177.149 ip4:67.109.66.68 ip4:198.179.134.238 ip4:107.20.247.57 ip4:207.87.182.66 ip4:199.66.248.0/22 include:cust-spf.exacttarget.com ~all". DKIM or SPF both have their own pros and cons. Since DMARC will fail for SPF, we may rely on DKIM, however, most mailing list managers also add footers to messages, or tag subjects with the list name, thus breaking DKIM signature verification. If you provide email delivery or hosting services for third-parties, they will have to add hostnames and IP addresses you use to deliver their messages to their own SPF records. Several real-life email architecture situations are discussed, and guidelines for implementing them on the Cisco Email Security product set. Email attacks are on the rise, and several organizations have implemented different email authentication protocols like DKIM, SPF, and DMARC to help mitigate the risks of such incidents. , which helps you create the TXT record youll include in your DNS settings. SPF This guide describes three predominant email authentication technologies in use today - SPF, DKIM, and DMARC, and discusses various aspects of their implementation. DKIM or SPF both have their own pros and cons. At EasyDMARC, weve made the process easy for you with our suite of innovative tools, such as the. The single biggest problem of implementing SPF is to discover who is currently legitimately sending emails on your behalf. Sender authenticity is implied by having the From header signed. This may include regularly checking your SPF and DKIM records, monitoring your email logs, and testing your email infrastructure to identify any issues.