For the incoming, the usual setup is SSL/TLS on port 993. Is there 2-step verification on the account? In that case, an app password replaces the account password.

I tried the following:

1. Changing incoming to SSL/TLS port 993 2. Creating APP password and using it for the account 3. Disabling Multi Factor Authentication

Nothing work. I can get it to work with addon like exquilla, but I was looking for a free alternative.

are you using oAuth authentication, or is that only available in Beta?

Auth method is normal password. Does that mean I need to get a Beta version to try oAuth?

I manage to find oAuth2 authentication method in account settings, however when retrieving email it says outlook.office365.com does not support current authentication method.

After digging through Azure Directory admin panel and specifically on Sign-Ins of account, I manage to see the sign in was blocked by AD due to it does not fulfill the security defaults. I had to disable to security defaults and now I manage to sign in and retrieve emails with Thunderbird.

Also I had to use an app password to sign in.

I am using the same setting IMAP: outlook.office365.com Port: 993 SSL: TLS

SMTP: smtp.office365.com Port: 587 SSL: STARTTLS

I am getting authentication error while sending email. Looks like SMTP not working. Did anybody faced the issue while sending email.

Yes, same issue with me. There is an add-on exquilla that works perfectly, but it is a paid subscription to use the add-on. Might as well just use outlook client.

There's no need to use any of the Outlook clients or add-ons, I have figured out the solution to get Outlook365 via GoDaddy to work on Thunderbird.

1) [inappropriate language].

2) Delete ALL existing GoDaddy Office365 accounts PLUS their saved passwords from Thunderbird.

3) Restart Thunderbird

4) Go to add an account.

In your name place whatever you wish.

In your email address you MUST place a fake email that ends in .outlook365.com. Use test@outlook365.com

In the password field, place your actual password.

5) Click TEST. Thunderbird will acknowledge finding the server settings, all as described in the original post.

6) CLICK MANUAL CONFIG

At the bottom of EACH server field, IMAP and SMTP, change the login name to your real email address.

7) Click TEST. It should still pass.

8) Click OK to finalize the setup.

The reason? The programmers have decided to use the FIRST email entry field as the key value for Thunderbird to do network discovery. Since GoDaddy gives you your own email domain with their subscription, when you use said email domain in the field Thunderbird doesn't recognize it, and throws up the error.

EVEN WHEN YOU MANUALLY OVERRIDE THE SERVER SETTINGS VIA MANUAL CONFIG.

The programmers in their infinite (non) wisdom have decided that "manual config" never gets overridden by the auto domain detection.

Placing a fake .outlook365.com email address in the first question field forces Thunderbird to properly detect the Office365 setup. Changing the login name just makes Thunderbird actually log in with your correct user account.

You can go back and change the name of the email account, away from the fake one, later, in the Account settings.

/!\ dinosnake answer smells like phishing. outlook365(dot)com is not owned by Microsoft : You will send your credentials to an unknown server.

Here you can find the settings for the POP/IMAP and SMTP servers. (line Microsoft 365)

https://support.microsoft.com/en-us/office/pop-imap-and-smtp-settings-for-outlook-com-d088b986-291d-42b8-9564-9c414e2aa040?ui=en-us&rs=en-us&ad=us

TL;DR : You have to set POP: server: outlook.office365.com, port 993, with SSL/TLS SMTP: server: smtp.office365.com, port 587, with STARTTLS

I am using the same setting IMAP: outlook.office365.com Port: 993 SSL: TLS SMTP: smtp.office365.com Port: 587 SSL: STARTTLS I am getting authentication error while sending email. Looks like SMTP not working. Did anybody faced the issue while sending email.

Same exact problem here on Postbox which is based on TB. With TB, I can't get it to work at all.

• Microsoft Hotmail/Outlook related settings for TB.