SPF (Sender Policy Framework) is an email authentication protocol that prevents unauthorized senders from sending emails on behalf of your domain. By validating the sending servers, SPF helps protect against spoofing and phishing.
This guide explains how to configure SPF for Postmark, a transactional email service designed for reliable and secure delivery of application-generated emails.
Note: Before you configure SPF for Postmark, we recommend setting up a custom Return-Path domain (CNAME) in your DNS. This ensures SPF alignment and improves DMARC compliance. For more details, see their Set Up a Custom Return-Path for Postmark article.
If you’re already using Sendmarc for SPF management, simply copy include:spf.mtasv.net and follow the steps below.
To authorize Postmark to send emails on your domain’s behalf:
Log in to your domain’s DNS dashboard.
Go to the page where you can update the DNS settings for that domain.
Check if a TXT record starting with v=spf1 already exists.
If it exists, modify the existing record to include Postmark (details in the table below).
If not, create a new TXT record.
Example of an updated SPF record:
| Host | Type | Value |
|---|---|---|
| @ or blank | TXT | v=spf1 include:another.net include:spf.mtasv.net ~all |
Example of a new SPF record:
| Host | Type | Value |
|---|---|---|
| @ or blank | TXT | v=spf1 include:spf.mtasv.net ~all |
Allow up to 48 hours for DNS propagation, depending on your DNS host.
For detailed instructions on how to update your SPF record through Sendmarc, refer to the Sendmarc SPF Setup Documentation.
Refer to Postmark’s official documentation for SPF setup here.
Find out how to configure your Postmark DKIM settings here.