STARTTLS is required to send mail (Ubuntu, Office 365, DigitalOcean)

So, I’ve migrated a site over to a DigitalOcean droplet.
I used an all-in-one migration plugin to make life easier, and it did the trick (mostly).

I’ve got everything setup as it should. I have ports 22, 80, 443, 25, and 587 open.
But I keep getting the error message “STARTTLS is required to send mail”.
I’ve got Let’s Encrypt installed and the certs in place.

Not sure what else there is to do, as I can’t really find the info I need.

I’ve done a SSL report and it says: “This server supports TLS 1.3.”
https://www.ssllabs.com/ssltest/analyze.html?d=thefirm-network.com

Update: I managed to get this fixed by re-saving the Login details. Funny that.

• This topic was modified 3 years, 11 months ago by Quin. Reason: More info
• This topic was modified 3 years, 11 months ago by Quin. Reason: Updated for fix