Yes I know but then you need another Windows box and license.
But relaying via Postfix is also easy, once you know how to configure it...
I used this one to test it with G-mail first: https://www.howtoforge.com/tutorial/configure-postfix-to-use-gmail-as-a-mail-relay
This is for OWA 365 but very similar: https://www.informaticapressapochista.com/linux/configure-postfix-use-office365-smtp-relay-ubuntu-16-04/
Microsoft is not as cool as Google when it comes to accepting mails not being sent by the authenticated use so you have to change the headers a bit; they must be the same as the account you'll log in to OWA 365 or your message gets rejected: https://wiki.4psa.com/display/KB/How+to+change+the+From+header+for+messages+sent+by+Postfix
These last 6 weeks have been interesting because I learnt a lot about this nice NetXMS product but now my project's time's up.
But relaying via Postfix is also easy, once you know how to configure it...

I used this one to test it with G-mail first: https://www.howtoforge.com/tutorial/configure-postfix-to-use-gmail-as-a-mail-relay
This is for OWA 365 but very similar: https://www.informaticapressapochista.com/linux/configure-postfix-use-office365-smtp-relay-ubuntu-16-04/
Microsoft is not as cool as Google when it comes to accepting mails not being sent by the authenticated use so you have to change the headers a bit; they must be the same as the account you'll log in to OWA 365 or your message gets rejected: https://wiki.4psa.com/display/KB/How+to+change+the+From+header+for+messages+sent+by+Postfix
These last 6 weeks have been interesting because I learnt a lot about this nice NetXMS product but now my project's time's up.
