That message usually appears when all the information is not listed, causing Thunderbird to attempt to locate the information on its own. I suggest you click the 'manual' option and key in all the info. To ensure the basics are found, I suggest omitting the password.

Hi, Thank you for your reply. I tried your suggestion, unfortunately I keep receiving the same message.

what is the info to the right of the @ in the email address?

Sorry for the late reply. The info to the right of the @ in the email address is rjnexus.com

I suggest you repeat this and click DONE when complete. I believe that message only means that the info is not in the Thunderbird database.

I tried what you suggested, at the bottom left it says ‘Connected to us2.imap.mailhostbox.com’. Bottom right has a blue activity bar. After about 20 seconds it ends but there is nothing in the ‘inbox, deleted or outbox’. No other folders are shown so I’m guessing it hasn’t synchronized. Thank you for your help though.

I suggest you repeat this and click DONE when complete. I believe that message only means that the info is not in the Thunderbird database.

No it means that the new account wizard was not able to detect any settings in the ISPDB data base, via polling the published server location for a settings file for the account or by probing the server returned by the MX DNS entry for a server to get mail from or a server name made up using the domain from the email address.. Fundamentally the search for usable setting has come out as a failure. Where the domain is included in the ISPDB, it is generally a strong indication that there are firewall issues, usually software firewall issues as if say Thunderbird can not find setting for Gmail then the problem is clearly connectivity, hence firewall.

The secondary step of validating the settings and being unable to connect is usually an indicator of there being antivirus/firewall issues as well, the settings detected are used to try and initiate a normal mail account sign in. Failure here is often the issue of defective or self signed certificates used by antivirus products. The error message here about wrong username and server are rarely anything but red herrings. But from my reading of the setup routine, you have not made it to this step. You are stuck with unable to detect.

The failure to detect settings is rather common where hosted domains are concerned. Mostly because everything is done to a price and most of the things around encryption are done in a halfhearted manner. As is the server setups for mail. However by faithfully copying the settings from the provider as to domains server name and ports it should work. I would however recommend against using port 25. For the last 20 years it has been used as the server to server transmission port, not the submission port. It is also commonly blocked by antivirus product keen to prevent spam bots getting to send mail successfully should you some how get infected with one. So port 587 would be the appropriate one to use.

If you have an antivirus program that scans mail,I do not I use Microsoft Defender, you may well have to look into the settings and disable email scanning completely while you set up, or indeed disable the antivirus entirely as they try and scan encrypted connections which your provider has said you should use and errors relating to certificates do not reliably bubble up to a point you can see them.

At this point where you have forced a non working account to be created. I guess the best approach is to try and work out why it does not work, instead of lingering on the creation wizard.

So initially open the error console. (ctrl+Shift+J) press the trash icon on it's toolbar to clear it and press the get mail button for the account. Note any errors that appear while it gets to the no mail point of failure and post them here. Note there is a copy all messages if you right click in the error console to facilitate pasting them into a reply on the forum. If you try the process a few times and consistently see the same error , please point out what that error is.

If that gets us nowhere, and it might, then I will suggest full on logging of the IMAP protocol, but lets see if you can get something the easy way first.

Hi Matt, Thank you for your very detailed explanation. Previously I shut down the antivirus by the system tray – right click icon – antivirus shutdown, but was still having issues After reading your post I thought I’d try uninstalling it just to see, and well, Thunderbird could connect. So, it appears that shutting down this antivirus still leaves some part active. So, yes, you were spot-on about the possibility the antivirus is causing the issue. Also, as per your advice I changed the ports to 587. A huge thank you for your help.