Bypass Azure VM Port 25 limitation for internal communicaton

Question

Hello community!

I know from here: https://learn.microsoft.com/en-us/azure/virtual-network/troubleshoot-outbound-smtp-connectivity 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 (company.mail.protection.outlook.com)

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 smtp.office365.com 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

Chris

Answer 1

Hi

see similar thread on this query here:

https://learn.microsoft.com/en-us/answers/questions/1358541/how-to-fix-smtp-relay-issue-on-azure-vm?wt.mc_id=AZ-MVP-5005255

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

Hope this helps,

Thanks

Michael Durkan

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