Microsoft Exchange is broken in Thunderbird

Microsoft Exchange is broken in Thunderbird, and I do not know how to fix it. Best avoid using Microsoft Exchange for now.


Edited: 2021-03-24 08:12

I recently tried to setup e-mail in Thunderbird for Microsoft Exchange. I gave up.

The official documentation does not explain how to use POP3 or IMAP protocols properly, and as usual, Microsoft support forums do not provide any meaningful help.

Some discussion pointed in the direction that maybe the organisation admin had to enable support for IMAP and SMTP before it would work. But, after logging in to my user account on the web mail, i was not able to find anything indicating whether I could connect using standardized protocols. A list of protocols specifically enabled by the admin would have been great.

I did manage to connect to the IMAP server using SSL/TLS with OAuth2, but for some reason the SMTP server just refused to authenticate or send e-mail while falsely claiming the login details were inaccurate.

Also note that Microsoft Exchange does not support normal (basic) authentication with IMAP, POP3 and SMTP anymore. Instead it looks like we have to use OAuth2, and some clients may not support that.

The correct IMAP settings for Microsoft Exchange seem to be as follows:

Server name:
Port: 993
Encryption method: SSL/TLS

And if you prefer POP3:

Server name:
Port: 995
Encryption method: SSL/TLS

Both should use the OAuth2 authentication method. So far, so good.

The SMTP settings listed by Microsoft are as follows:

Server name:
Port: 587
Encryption method: STARTTLS

For SMTP this does not seem to work regardless of the authentication method used.

If you know of a solution, please add a comment and I will update the article with the information.

Microsoft Exchange support on Linux

The only alternative to IMAP on Linux is to use the Owl extension for Thunderbird; but this is an unacceptable solution, because it is not free. Why would anyone want to pay for such basic functionality?

I was unable to get the Evolution e-mail client to work, and KMail was broken due to Akonadi service not being operational — whatever that means. So, I was left with Thunderbird as the only free, and open source client.

E-mail is such a basic technology, so of course I think we should not pay money to use it. The Owl extension is also massively overpriced at 10 eur per year; if only it was a one-time-fee I might have considered it. I also have a principle of not paying recurring subscriptions for software; if I had to subscribe to everything on a monthly (or even yearly) basis, then I would have a negative income.

The real question is, why not just stick with standardized protocols? I personally have no need for Microsoft Exchange; IMAP and POP are obviously better, since they are more broadly supported by e-mail clients.

Please do not use Microsoft Exchange in your company unless you enable support for IMAP and SMTP.

Microsoft needs to support Linux

Back when I was still using Windows, I specifically stopped using Microsoft's e-mail clients because they have proven unreliable; the reason for this is that Microsoft occasionally ditches support for older, working clients, and replaces them with e-mail clients that are worse and take time to configure and learn to use. The worst part is that you might loose e-mail when switching clients, since it is difficult to backup and import e-mail messages.

First support for Outlook Express was discontinued, and later when Microsoft also ditched Windows Live Mail to replace it with a worse, build-in, mail app in Windows; of course users had no other choice than to switch to Thunderbird.

Much like Web Browsers has gone Open Source, e-mail clients can also benefit from being made open source; I simply no longer trust or use an e-mail client that is not open source; what if the company behind suddenly stops developing it? An e-mail client is so much an essential software that we can not run the risk of it suddenly breaking.

Some people actually still read their e-mail from a terminal; to some extent, that is also how I prefer to be able to read my e-mail, and if I can not, then it is a good sign that the e-mail provider is doing something wrong with their setup. Ideally, e-mail protocols should be open source as well.

Microsoft Exchange has an overly aggressive anti-spam

This is a different issue, and one that other popular services also struggle with; but it is also a good reason not to use Microsoft Exchange.

I tried sending an e-mail from my own e-mail server to my Exchange hosted e-mail account, and strangely it did not go into my Inbox, which meant that my e-mail client would not download it. It simply silently failed without notifying me about it.

Because of that, I fear I might actually miss important e-mail.

That is just completely unacceptable when you are using a "professional" service; and what worse is, I have not found a way to disable the broken anti-spam filter altogether. I suspect that is something only the organisation admin can do (if at all this is possible).

Ideally, individual users should be able to disable the broken spam filter entirely on their accounts.

Tell us what you think:

  1. How to fix this problem with Thunderbird, and a possible reason why it happens.
  2. How to configure your IMAP e-mail client to use AWS workmail, using Thunderbird as an example.

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