Форум сообщества Thunderbird

I had to delete and add back several accounts due to a change in servers (cox.net to yahoo.com). Prior to this I just had the All Folders, Local Folders and below. Now I have the Unified Folders and below, which are essentially a duplicate of the folders in the old All Folders. (See attached image) Not only is it making things confusing but I'm storing duplicate emails and it seems to be affecting performance, Thunderbird now randomly quits and restarts. So, how do I delete either the All Folders or the Unified Folders and move the few sub folders that are unduplicated into the remaining group?

I have cox comm. for internet and emails, they just changed their server to yahoo.com. Now I cannot sign into thunderbird to send or receive emails.

I find that when I click on links to take me to website through my email in Thunderbird that I will get an error message that reads "we could not verify the certificate, reason=wronghost"

But, if I copy link and copy into browser it works fine. There is a break in the Thunderbird email to the browser. This does not happen with all links but there are about three or four that I get regularly where it fails.

I have talked to a tech guy and we have tried different things and it always comes back to a break in Thunderbird email.

How do I fix this problem?

Thank you, Monica