Cisco ISE Guest portal email - SMTP issue

[icarimo]

Hello,

I have configured Cisco ISE with Guest portal using a sponsor authentication.
When I fill the user information in the registration form I get an error.

I did a wireshark capture and I noticed that the SMTP server is sending back a message saying "mail sent to the wrong office 365 region"

My SMTP server is in azure (probably in EU zone) and my PSN node is US.
Note: For the other PSN nodes in EU is working fine.

Has someone have this issue before and how it was solved?
Wireshark capture below:

[Flavio Miranda · Accepted solution]

@icarimo 

 Check this doc from Microsoft. Seems to describd your problem and provide possible solutions

https://learn.microsoft.com/en-us/exchange/troubleshoot/email-delivery/wrong-office-365-region-exo