I have a school provided email (email@example.com) that is located on an outlook server (pod#####.outlook.com) that I configured in Thunderbird using the settings provided by the web-based outlook portal. I am connecting via IMAP and can retrieve all email messages and synchronize all folder except the
Sent folder as it is tied to SMTP.
I've tried every configuration of the Outgoing Server Settings I could but none work. (SSL/TSL vs STARTTLS with each of the authentication methods)
Oddly, when I was configuring the email in Thunderbird it continued to fail when I specified the settings I got from outlook.com but succeeded in creating the account with incorrect IMAP settings that it detected by polling the server. It wasn't working after completing the set up so I changed the IMAP settings to what they should have been and now as I mentioned, I am able to retrieve mail.
This has never been a problem before and I have used several Outlook/Thunderbird clients as well as android mail clients without many problems. I can send mail on my phone and in Outlook.
Update: I was able to send a test message a few times but it still could not copy the message to the Sent folder. I also seem to have 3 Sent folders (2 "Sent" and 1 "Sent Items"). I was able to view one Sent folder's contents so I thought that one worked but after setting the outgoing mail to copy the message to the supposedly working Sent folder, I am now no longer able to view the contents. Whats going on here?