Error sending email Unrecognized authentication type AUTH LOGIN

Hi All,

We got a Service Center Error Log related to sending of email from Server.

Error: "Error sending email 21: 504 5.7.4 Unrecognized authentication type AUTH LOGIN"

This was working when we haven't migrated to O365, but after migration to O365 it seems that some authentication are failing. Note that I have revisited/reconfigured the Administration part of the Email in the Service Center.

Appreciate your help to this. Thanks!


Raymond Reyes

Hi Raymond,

This seams to be an issue with your SMTP Server, not with the configuration in OutSystems.

I found on some forums other people with a similar issue and for some of them the following steps worked:

"Disable SMTP TLS support


Enable SMTP TLS support


Then it worked fine."

You can find more details for instance on this topic:

Let me know if this helped.




Thank you for your response Ana!

It is already working now, although we didn’t follow the suggestion to Disable/Enable the SMTP TLS support. We just removed the username and password in the Service Center's Email Configuration setup. Thanks!


Raymond Reyes


This bug is stil in Service Center (Version

If you change Username and Password, you will start getting "Unrecognized authentication type AUTH LOGIN", but if you clear the fields, save it and then input them again, it will work.