15.2 enable to send mail to smtp.office365.com

Hi Christophe,

Can you please identify what has been changed since it was working last time: Windows updates installed on Alliance servers / any Alliance updates applied lately / configuration or updates on office365 side?

Thank you,

Gene

We can take it to the Support level  if needed (please ask to reassign a ticket to Gene and I will take it from there). We can publish our solution here afterwards.

I will open a case. there is no change on Alliance or on windows. i guess but i’am not sure at all ,there is a change in azure/office 365  on TLS protocol but i’m not an expert

Rgds

Christophe

Christophe,

Most likely this issue is related for Microsoft is disabling TLS1.0 and 1.1 on office365:

https://docs.microsoft.com/en-us/microsoft-365/compliance/tls-1-2-in-office-365-gcc?view=o365-worldwide

If you are on Premises we will need to identify with your tech folks if your servers are prepared (updates, etc.) for TLS1.2

Another thing I would check though I have not heard this was specifically the case is whether MS also disabled access via port 25.

I know many companies moved away from this very old standard port used for smtp.

I thought Microsoft used port 587 for Office 365 with security using TLS?