Postmaster Guidelines

Postmaster Guidelines

Postmaster Guidelines are resources published by different email service providers (AOL, MICORSOFT, GOOGLE, YAHOO, FACEBOOK, ETC) to help businesses to effectively communicate with the emails accounts they service. These guidelines tell you everything you need to know and configure in your email to ensure the best possible deliverability rates. A lot of the information and best practices published at the different email service providers overlap. So once you change everything to, let’s say, Google, you are also improving your deliverability rate at the other ESP's as well. These guidelines are always evolving, so you should review them on a quarterly basis.

Great more work! Where are these postmaster guidelines located?

Below are the links to some of the more popular Email Service Providers; this is not a complete list, but it covers the majority of the ESP's located in the USA.
  • AOL Postmaster - Bulk Sender Best Practices & Guidelines
  • Gmail - Bulk Senders Guidelines
  • - Policies, Practices, and Guidelines
  • Yahoo! Mail Bulk Sender Guidelines
  • AT&T Postmaster
  • TWC Postmaster - General Guidelines
  • Road Runner Inbound Sending Policy
  • Facebook Sending Policy
  • Cox High Speed Internet Postmaster Guidelines
  • United Online Delivery Guidelines
  • BlueTie's Postmaster Guidelines
  • BOL Mail Postmaster Guidelines
  • Frontier Postmaster Information Page

How do I tell that if I'm following all the postmaster guidelines?

There’s no surefire way to tell if you're meeting all the guidelines of all the individual ESP Providers, but just being aware of them makes you a better email sender. These guidelines change as email changes. Unlock the Inbox has an automated testing tool that will tell you if your email is configured properly from a Standards and Authentication perspective, which is a large part of these guidelines. You can read more about our tool here: Email Authentication Tester  (from  

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