Suped
How do I align SPF authentication with my sending domain in Google Postmaster Tools?
Summary
To align SPF authentication with your sending domain in Google Postmaster Tools, it's crucial to ensure that the domain used for sending emails (5321.MailFrom or Return-Path) matches the domain authorized in your SPF record. If these don't match, there's no authentication connection, and you should ask your email service provider to sign with your domain (or a subdomain). This involves publishing an SPF record in your domain's DNS settings, specifying authorized mail servers and domains. Use Google Postmaster Tools to verify the legitimacy of emails. When DMARC is enabled, SPF aligns with the visible 'From' domain (5322.From). Understand that SPF alignment has strict and relaxed modes. Preventing spoofing is a key goal, and remember to gather authorized sending domains, create the SPF record, add it to your DNS, and test the record. Employ SPF, DKIM, and DMARC for enhanced security.

Key findings

  • Alignment is Key: Ensuring the sending domain matches the domain authorized in the SPF record is vital.
  • Authentication Chain: There must be a clear authentication connection between the sending domain and the headers posted.
  • Publishing SPF: You need to publish an SPF record that specifies the mail servers and domains authorized to send email on your behalf.
  • DMARC alignment: When DMARC is enabled, SPF works on the visible 'From' domain (5322.From).
  • DKIM and DMARC: SPF is a form of email authorization, but DKIM and DMARC are the strongest forms of email authorization.

Key considerations

  • Configure the DNS: You need to configure your domain's DNS records properly, updating an SPF record to include all the authorized mail servers.
  • Test it works: Checking your SPF record is vital to making sure it is set up properly.
  • Prevent spoofing: Take steps to help prevent spammers from sending messages with forged addresses from your domain.
  • DMARC policy: Use DMARC with an SPF policy, in addition to SPF itself, in order to best help improve your email deliverability
What email marketers say
11 marketer opinions
To align SPF authentication with your sending domain in Google Postmaster Tools, it's crucial to ensure that the domain used for sending emails (5321.MailFrom or Return-Path) matches the domain listed in your SPF record. This alignment helps prove the legitimacy of your emails, prevents them from being marked as spam, and improves deliverability. Key steps include configuring your domain's DNS records with an accurate SPF record that includes all authorized sending sources, and verifying the SPF record using online tools. When DMARC is enabled, SPF works on the visible 'From' domain (5322.From). Employing SPF, DKIM, and DMARC in conjunction are also crucial for DMARC alignment and enhanced email security.

Key opinions

  • SPF Alignment Importance: SPF alignment is critical for ensuring emails are not marked as spam and for improving overall deliverability.
  • Domain Matching: The sending domain (5321.MailFrom) must match the domain listed in the SPF record for proper authentication.
  • DMARC Impact: When DMARC is enabled, SPF alignment works on the visible 'From' domain (5322.From).
  • DNS Configuration: Correctly configuring DNS records, including the SPF record with all authorized sending sources, is essential.
  • Verification: Using online tools to verify the SPF record is important to ensure it's set up correctly.

Key considerations

  • Monitor: Regularly monitor your SPF setup to address potential issues and changes in sending sources.
  • DMARC: Consider implementing DMARC alongside SPF and DKIM for enhanced email security and deliverability.
  • Sending Domain: Identify and include all authorized sending sources in your SPF record to avoid deliverability issues.
  • Authentication Headers: Understanding headers when looking at SPF, DKIM and DMARC is vital to ensure proper email deliverability.
Marketer view
Email marketer from Postmark App responds that to align SPF authentication with your sending domain in Google Postmaster Tools, you need to configure your domain's DNS records properly. This involves creating or updating an SPF record that includes all the authorized mail servers or services that send emails on behalf of your domain, ensuring SPF alignment for better deliverability.
8 Sep 2023 - Postmark App
Marketer view
Email marketer from Mailjet explains that SPF alignment is important because it helps to ensure that your emails are not marked as spam. When SPF is aligned, it means that the domain used to send the email matches the domain listed in the SPF record. This helps to prove that the email is legitimate and not a phishing attempt.
12 Oct 2023 - Mailjet
What the experts say
4 expert opinions
To align SPF authentication with your sending domain in Google Postmaster Tools, it is important to ensure the domain used in the 'Mail From' address aligns with the authorized domain in the SPF record for proper authentication. If there's no authentication connection, request the email service provider (e.g., Socketlabs) to sign emails with the correct domain, register that domain with Google Postmaster Tools, and publish necessary DNS records. Using DMARC along with SPF enhances email deliverability and stream authentication. While SPF provides email authorization, DKIM and DMARC offer stronger authentication methods, so configuring all three is vital for secure mailstreams.

Key opinions

  • Alignment Importance: Proper SPF alignment is vital for improving email deliverability and building a positive sender reputation.
  • Authentication Connection: Ensuring a clear authentication connection between the sending domain and email headers is critical.
  • DMARC Enhancement: DMARC complements SPF by providing an additional layer of verification and authentication for mail streams.
  • DKIM and DMARC Strength: DKIM and DMARC offer stronger forms of email authorization compared to SPF.
  • Domain Registration: Registering your sending domain with Google Postmaster Tools is an important step to align SPF and other authentication mechanisms.

Key considerations

  • Domain Signing: Ensure your email service provider signs emails with the correct domain ('d=' tag) to establish authentication.
  • DNS Records: Publish necessary DNS records, including SPF and DKIM records, to properly configure email authentication.
  • SPF Policy: Implement a strong SPF policy, and consider adding DMARC to enhance email deliverability through improved verification.
  • Complete Authorization: Configure SPF, DKIM, and DMARC for comprehensive email authorization and secure mailstreams.
Expert view
Expert from Email Geeks explains there's no authentication connection between stockearnings-newsletter.com and the headers posted. To fix this, ask Socketlabs to sign with the d= of stocksearnings.com (or a subdomain) and register stocksearnings.com with Google Postmaster Tools, publishing DNS records for the DKIM public key and domain verification.
18 Aug 2024 - Email Geeks
Expert view
Expert from Word to the Wise explains that SPF (Sender Policy Framework) is a form of email authorization, but that DKIM and DMARC are the strongest forms of email authorization. It is important to configure all of these to ensure safe and accurate mailstreams.
21 Oct 2023 - Word to the Wise
What the documentation says
4 technical articles
To align SPF authentication with your sending domain in Google Postmaster Tools, you need to publish an SPF record in your domain's DNS settings. This record lists authorized mail servers and domains that can send emails on your domain's behalf. Google Postmaster Tools uses this record to verify the legitimacy of emails. SPF alignment has strict and relaxed modes; strict mode requires an exact match between the 5321.MailFrom domain and the organizational domain, while relaxed mode only requires the 5321.MailFrom domain to be a subdomain. The goal of SPF is to prevent email spoofing by validating the sender's IP address. Steps to take include gathering authorized sending domains, creating the SPF record, adding it to your domain's DNS, and testing the record.

Key findings

  • SPF Record Publishing: Publishing an SPF record is essential for authenticating emails.
  • Authorized Mail Servers: The SPF record specifies authorized mail servers and domains.
  • Google Postmaster Tools Verification: Google Postmaster Tools uses SPF to verify email legitimacy.
  • SPF Alignment Modes: SPF alignment has strict and relaxed modes.
  • Preventing Spoofing: SPF helps prevent email spoofing by validating the sender's IP address.

Key considerations

  • Record Creation: Gather authorized sending domains and create an accurate SPF record.
  • DNS Addition: Add the SPF record to your domain's DNS settings.
  • Record Testing: Test the SPF record to ensure it is functioning correctly.
  • Alignment Mode Choice: Choose between strict and relaxed alignment modes based on your domain structure.
Technical article
Documentation from RFC shares that SPF (Sender Policy Framework) allows a domain to authorize mail servers to send email on its behalf. An SPF record is published in the DNS and specifies which IP addresses or domains are permitted to send emails using that domain name.
14 Mar 2025 - RFC 4408
Technical article
Documentation from EasyDMARC shares that SPF alignment has two modes: strict and relaxed. In strict mode, the 5321.MailFrom domain must exactly match the organizational domain. In relaxed mode, the 5321.MailFrom domain only needs to be a subdomain of the organizational domain.
27 Aug 2021 - EasyDMARC
Start improving your email deliverability today
Get a demo