Email Domain/Account Issues

Has anyone else been having an issue with emails not being sent?

I tried to check and got the following error
image

Tried 2 different email domains (one microsoft, the other independant) but same result for both.

Emails were sending fine a few days ago.

Hello,

we have used microsoft office 365 accounts for it with SMTP the settings are set the following way:

Thanks, think the issue might be my install as I have tried the same settings as you have above and another host which uses their own, both times the settings are accepted but the result in the same error message when trying to send any emails.

I am running the development branch, so maybe the issue is there.