Bypass Azure VM Port 25 limitation for internal communicaton

Christopher Stainczyk 40 Reputation points

Hello community!

I know from here: thats it's not possible to open port 25 outbound from a azure vm if your are not having a enterprise agreement. We need to send mail from a azure vm to exchange online (

I know it's a bit optimistic but is there maybe any way to have a "direct" route from a azure vm to exo and use port 25? Problem is that over 587 is not possible, because we cannot use smtp authentication. We have to use TLS oder IP-based authentication. This could be done by using a third party smtp relay, but it would we much nicer if the mails don't "leave" azure.

Thank you and have a good day


Azure Virtual Machines
Azure Virtual Machines
An Azure service that is used to provision Windows and Linux virtual machines.
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Azure Firewall
Azure Firewall
An Azure network security service that is used to protect Azure Virtual Network resources.
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  1. Michael Durkan 12,156 Reputation points MVP


    see similar thread on this query here:

    SendGrid may be an option for you instead as it accepts unencrypted and TLS connections

    Hope this helps,


    Michael Durkan

    • If the reply was helpful please upvote and/or accept as answer as this helps others in the community with similar questions. Thanks!
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