Hi,
Up until now, my company was using one of our Office365 account as config for the atlassian mail server functionality (also in other Atlassian products).
Because of the extreme amount of e-mails now located in the "Sent" folder of this e-mail (mine), I am trying to use another way. For now, we don't want to buy a license just to use as a dummy sending e-mail.
I've found this documentation for Office 365. The Option 2 seems intersting to indeed avoid paying for a dummy mailbox.
I've changed my TXT DNS as advised, using Bitbucket's server IP and I've configured Bitbucket as such :

I've tried with and without the username set to equal the "Email from" field, but it doesn't work.
In the logs, it says :
java.net.ConnectException: Connection refused (Connection refused). Failed messages: com.sun.mail.util.MailConnectException: Couldn't connect to host, port: domain-com.mail.protection.outlook.com, 25; timeout 30000;
I've checked with a DNS tool to be sure the DNS config was propagated. Of course, my config is not using domain-com, but a real one.
So, is this method supported by atlassian products ? If not, could it be, so we can use any email we want without having actually to create it as a mailbox and pay for the license ?