Firewall must allow Thunderbird access to internet.

IMAP Incoming mail server : imap.tiscali.co.uk Incoming Port 993 Connection Security: SSL/TLS Authentication Method: Normal Password User Name = full email address username@tiscali.co.uk

POP Incoming server: pop.tiscali.co.uk Port: 995 Connection Security: SSL/TLS Authentication Method: Normal Password User Name = full email address username@tiscali.co.uk

Outgoing mail server smtp.tiscali.co.uk Outgoing Port 587 Connection Security: SSL/TLS Authentication Method: Normal Password User Name = full email address username@tiscali.co.uk

Not sure if the tiscali servers are using up to date TLS for their imap/pop/smtp servers, although they probably do for the website/webmail access. Please read info - which you can test to see if it works. No harm done if it fails as you can reset it.

• https://support.mozilla.org/en-US/kb/thunderbird-78-faq#w_after-upgrading-to-thunderbird-78-i-cannot-get-or-send-email-messages

Then restart Thunderbird.

Thanks for that, but I'm afraid it didn't solve my problem.

An IT contact put me onto the solution, however, and it turns out that simply copying and pasting the profile onto the new laptop does not allow profiles to be recognised. It needs to be put into its own folder on C drive somewhere. It has to be done using Profile Manager, which I had to do by running "C:\Program(space) Files\Mozilla(space)Thunderbird\thunderbird.exe" -P (do not use brackets or type the word space-I inserted this for clarity due to lack of room on the composing screen). This takes you to a Create Profile screen, from which it is straightforward, choosing the folder where you placed your profile.

I've left this case as unsolved in case anyone needs to follow it.

Thanks.