Форум поддержки Thunderbird

I had a huge problem with M Outlook. In addition it has locked me out of my Office 365 package and I'm not getting help or support. Luckily I had backup completed before the problem. I changed to Thunderbird (using pop3), which I find very good. The back up is approx 8 GB but with many duplicates which I need to clean up. When I click import it seems to limit the file size to 2 GB. How can I import this backup file into Thunderbird to enable me to access the emails, clean up the many many duplicates and reduce the size? I await help, Thanks in advance

Hi, As of yesterday I am unable to send emails out. I keep getting this message below. I have gmail on same computer and that works fine. I am able to receive emails but can't send. Please help