I would suggest if you are in that situation that you avail yourself of the automation that is available! It does involve placing certain information on the server to be read at install time.

Over the last 10 years of Mozilla reorganizations the information about auto config has been fragmented and is not anything like it should be, however Thunderbird uses auto configuration XML files to configure accounts. These on the whole are from https://autoconfig.thunderbird.net/v1.1/ however there are other locations checked before Thunderbird looks there.

First Thunderbirtd looks at Config files on harddisk, in installdir/isp/emailaddressdomain.xml , e.g. C:/Program Files/Mozilla/Thunderbird/isp/example.com.xml . Where installdir is defined as the directory the executable is in. Then http://autoconfig.emailaddressdomain/mail/config-v1.1.xml?emailaddress=emailaddress , e.g. http://autoconfig.example.com/mail/config-v1.1.xml?emailaddress=fred@example.com,

Then it tries http://example.com/.well-known/autoconfig/mail/config-v1.1.xml, and see whether that host/URL exists. The returned file must have the ConfigFileFormat

Finally is reaches out the the thunderbird.net location before trying to guess settings.

Source if it help you understand the process is here. https://searchfox.org/comm-central/source/mail/components/accountcreation/content/accountSetup.js

If you are setting up hundreds, then my suggestion is implement local change to use config files, either locally, on the web server of the mail domain name. either as a sub domain or as a URL on the domain.

It seems when we setup the mailbox that all of the settings are quickly pulled in from the mail server. Thunderbird finds everything it needs but as of the latest release it chops off the domain name from username and causes an infinite hang for some reason.

When we try to configure manually it says the server already exists so then we have to restart Thunderbird and try again.

I have not seen anyone else complain about this so I guess I am the only one experiencing this problem and it could be a Plesk email server issue I suppose.

have you looking in outgoing servers(SMTP)v to see if the plesk server exists?

I know there was a change in 102 where the new account wizard is supposed to provision an SMTP server entry for each now account. Older version reused the same one which cause sending issues on some servers.

I would also appreciate a log of your attempt to add the account. just to clarify what is the point of failure.

I have some instructions for logging here https://thunderbirdtweaks.blogspot.com/2021/10/logging-new-account-wizard.html

I deleted your duplicate question. Just so you know.

I will try and look for any logs to show the problem... in the meantime I attached screenshots that show how Thunderbird is chopping off the email address username and causing the infinite wait for checking password... if you manually configure the account and put the domain name back into the username then it works like it used to is all previous versions. But this is confusing all of our users that need to add an email box. Thanks.

Also, tried running the logging in the console and it failed a few checks for auto configure but it did find the correct mail servers and configuration. I have attached screenshots.

It would appear to me the best approach would be for the web site to have an XML file for the wizard to find with all the settings in it at one of the locations it checks on your server.

The file format is covered here https://wiki.mozilla.org/Thunderbird:Autoconfiguration:ConfigFileFormat

Woohoo!! That did the trick and it works perfectly now!

<username>%EMAILADDRESS%</username> was the key that we needed and for some reason Thunderbird started defaulting to the user part of the mail address.

Anyway, all is good and I learned how to make Plesk's mail server play nice with Thunderbird.