Thunderbird

[#1]

My Thunderbird account was recently uninstalled by accident. I have re-installed it using all the previous data, which worked faultlessly for many years. Now I cannot send/receive messages.
I have spoken to Plusnet tech staff, who claim all is well with my account/username/password. I have checked my security system, as well as my knowledge will allow, and there does not appear to be a problem.
I can log in to Plusnetw ebmail with no troulble and receive/send.
Mozilla have not been approached, as I cannot find a way to e-mail/talk to anyone.
Can anyone of you assist please.?

[#2]

Usually its a case of having the .thuderbird directory there.
Thats where settings are saved in a random diretory_name.default
At least thats how it is on linux.
Problem is if thunderbird is fired up without that structure - it creates a whole new structure, and uses that. This means it isn't configured ...

[#3]

Right click on the account, choose settings, re-enter your account details, including the server details.