The Postmaster: an indispensable concept for managing email deliverability

In this article, we're going to tell you all about the postmaster! In the jargon of email, the postmaster is not only a the postmaster (yeah, right...), but it's also an important email address for contact the technical managers of the email infrastructure and in some cases one or more web pages containing important information to send emails to a deliverable destination.

This is an important concept to understand if you're interested in email deliverability. For example, in a deliverability analysisWe'll need to check that this email address exists, and we'll need access to certain information on the postmaster pages of webmails and ISPs. But first things first!

Want to learn more about deliverability? Read our complete guide to email deliverability.

What is the postmaster when it comes to email?

Originally, the postmaster was the person (or group of people) that is in charge of email infrastructure management and administration of an organization.

By extension, postmaster also refers to theemail address ( which allows you to contact the administrators of the email infrastructure. The term postmaster is also used to describe documentation pages explaining how an email infrastructure works. These postmaster pages enable email senders to understand the rules and practices of this email destination (bounces, filtering, reputation, etc.).

The role of ISP and webmail postmaster pages

For many years, the postmasters of messaging services have been developing pages on their web sites to explain the main rules for email delivery on their servers. Over time, these pages have expanded to include :

  • Means ofget in touch with a support service or messaging administrators
  • A rules documentation techniques that govern the mail server (sending speed...), categorizing bounces, email authentication rules, …).
  • A documentation on best practices related to deliverability that you should respect to have a good email reputation.
  • From analysis tools to understand whether your domains and IP addresses are blocked, how reputable your IPs and domains are, how many spamtraps you get, ...
  • Technical procedures for set up an email feedback loop (to receive information on spam complaints) or access a whitelist.
  • ... and many other things depending on the ISP and Webmail: BIMI validation, whitelist, data flow...

List of postmaster pages for messaging services

The posmaster pages of ISPs are very uneven: some are very complete, while others are simply non-existent. Here's a list of the Postmaster pages of ISPs that offer one:

Gmail postmaster page

Google's postmaster pages offer a wealth of tools and information. The only very light section is the one for contacting their support. Don't expect a reply ;-);

Useful links for deliverability at Gmail :

Postmaster page from Microsoft or SNDS (Smart Network Data Service)

Microsoft offers a wide range of postmaster services for its consumer e-mail products (, Hotmail, MSN, etc.) to help message senders do their jobs better. This includes reputation information (reputation levels per IP, spamtraps volumes...), the ability to set up a complaints feedback loop (JMRPP), documentation and a support form for contacting Microsoft's abuse department.

Useful links for Hotmail/Outlook deliverability :

Office365 Postmaster services

Office 365 postmaster services are limited to a form to request an IP address unblock. It's here:

Yahoo! postmaster page

Yahoo! is one of the most comprehensive webmails when it comes to Postmaster services. We find the classic documentations and the possibility of receiving information on spam complaints, but also an information feed called "Performance Feed" which allows you to receive information on marketing performance and inbox placement.

Useful links for deliverability at Yahoo!

Apple's postmaster page

Apple, via its iCloud service, offers its users email inboxes. The service was previously known as "". Unfortunately, the postmaster service can be summed up in a small documentation page, which you can find here :

There is a support service that you can reach via this email address: postmaster page

LaPoste's webmail is an exception among French ISPs and webmails. offers a page of resources dedicated to email senders, on a par with the best players: IP feedback loop, documentation on return codes, best practices, contact form...

Useful links for deliverability at :

Orange abuse service

Orange doesn't really have a postmaster page, just a presentation of the ISP's abuse service. However, it is possible to contact the Orange anti-spam service by e-mail or via a form.

Useful links for deliverability at Orange :

Need help?

Reading content isn't everything. The best way is to talk to us.'s postmaster page

In a style that hasn't changed in many years, the ISP Free offers a small documentation of the main bounce codes that can appear in the event of a Free block. You can also test your IP addresses to see if they're blocked, or contact Free's Postmaster service;

Useful links for Free deliverability :

Proofpoint's postmaster services

Proofpoint is one of the leading anti-spam services used in B2B, mainly by large corporations. It's worth noting that Proofpoint equips Apple for its anti-spam. Few services available, just a form to check the reputation of your IP address: and a FAQ :

Other resources you may find useful

There are many more postmaster pages, as well as other services related to deliverability. Here are a few additional resources:

What is the purpose of the postmaster email address?

For you, the advertiser, this address will be very useful because it will :

  • Allow your users to contact you to report a technical problem on your mailing (e.g. a link not working) or on your website (e.g. a problem accessing a user account).
  • Allow you to contact the administrator of a domain in case of delivery problems.
  • Allow you to set up the feedback loops (Yahoo for example).
  • Allow you to remove a blocklist email.
  • To allow to implement monitoring tools as NSDS.

Just like the address abusethe address postmaster is a technical address described in several RFCs (which describe Internet standards): RFC822 & RFC2142 & RFC5321.

In addition to being mandatory for any domain, it is usually specified to receive queries and reports. In short, it is used to contact the network administrator of a domain 🙂

RFC specifications for the Postmaster address

Thus, it must exist for any organization with a domain name (whether it is the main domain name or a sub-domain) and an MX server. By which I mean you (who are reading this article), Badsender, La Poste, Gandi, Engie... all (logically) own one. In addition to existing, e-mails arriving in this mailbox must be read and processed.

The disadvantage of the Postmaster address

It could be akin to a junk address, you will receive a lot of spam on this address and you'll have to sort out legitimate and unwanted e-mails! But hey, it's worth it.

Is the Postmaster address really useful?

I think I've also stated enough above to say that the answer is obviously: YES 🙂

How to verify that the Postmaster address exists?

Verification made thanks to :

Postmaster address verification at

There is an advantage and a disadvantage to using this tool:

Advantage: If the server's response is synchronous (I ask and am immediately told whether the address is valid or not), you know right away if the address exists.

Disadvantage: If the server response is asynchronous (I ask and am told it's ok but a few hours/days later I get an email telling me the address doesn't exist), you won't know if the address exists or not.

Send an e-mail directly

Checking with my Gmail address We send an e-mail to the address "postmaster@" and we ask for the validation of the good reception:

Send an e-mail to the domain's Postmaster address to verify that it exists

Here again, you will have an advantage and a disadvantage:

Advantage: If the administrator is friendly and checks the emails in this mailbox, he/she will reply to you.

Disadvantage: If he/she is not (friendly) or does not check the mailbox, you will never get a reply to your e-mail.

In this case, ask your IT department (or the support of your host) if this address exists and that you have access to it.

The author

2 réponses

  1. Hello,
    Is the postmaster address also useful if you are routing with a shared or dedicated IP?

  2. Hello Maxime,
    The Postmaster address is valid for any domain, regardless of the type of IP you use. As long as you create a domain, this address must exist.
    Kind regards,

Laisser un commentaire

Your email address will not be published. Les champs obligatoires sont indiqués avec *