A guide to best practices for Sender Policy Frameworks (SPF)

The Sender Policy Framework (SPF) is an email-authentication technique which is used to prevent spammers from sending messages on behalf of your domain. With SPF an organization can publish authorized mail servers that is which is mail servers are authorized to send mails on behalf of your domain.

Managing SPF records can be challenging. There are several issues that can arise from a poorly configured record in terms of email delivery.

Let’s take a look at a few best practices for SPF records in more detail

  1. Third-party senders should use the “Include” mechanism:

Make sure you include the SPF records of any third-party email services you are using, such as marketing platforms or CRMs. This assures that emails sent using these services are authorised. For example, if you are using services like Zoho you need to add include “include:one.zoho.in” in your domain SPF record.

  • DNS Lookups Limit:

DNS lookup for SPF record should not exceed 10 DNS lookups. If you have more than 10 lookups in your record, a permanent error could be returned during the SPF authentication process. DMARC treats that as fail since it’s a permanent error, and all SPF permanent errors are interpreted as fail by DMARC. Avoid nested includes.

  • Avoid Duplicate SPF TXT record:

you can only have a single DNS TXT record which begins with “v=spf1”. Having multiple SPF records will result in permanent error.

  • Character Limit for SPF:

SPF records have a 255 character string limit in Domain Name System (DNS). If you have an SPF record with a string longer than 255 characters, it will fail the SPF authentication check.

  • Regularly Update SPF Records:

Keep your SPF records up to date. If you change your mail servers or use third-party services to send email on your behalf, update your SPF records accordingly.

  • Add SPF record on DNS in ‘TXT’ type:

Make sure that you have added SPF record of your organization domain on DNS under ‘TXT’ type. Don’t use the ‘SPF’ DNS record type. This has been deprecated in favor of TXT records.

  • Avoid the use of PTR mechanism in SPF record:

The use of PTR mechanism is heavily discouraged as it is slow and unreliable. it is advisable to avoid including PTR type mechanisms in your SPF record.

Adhering to optimal practices in configuring and maintaining SPF records is instrumental in mitigating email spoofing and ensuring the reliable delivery of legitimate emails to the recipient’s inbox.

Please refer to the URL to understand more about What are the limitations of the SPF record? AND SPF record syntax

Explore our SPF Record Generator Tool / SPF Record Checker to proactively prevent SPF-related issues. Visit now for simplified SPF record creation and optimal email authentication.

If you have any questions or need assistance with email authentication or SPF-related queries, don’t hesitate to reach out to us at +91-9820116312 or drop an email to info@progist.net