Everything was working until I updated to 91.1.1. Verizon, Gmail, and Yahoo all worked and but can not send email with any of them but can receive email with them When I used the email configuration tool with 91.1.1, I could not complete because i got message 'INCOMING SERVER ALREADY EXISTS" Also got message "OUTGOING SERVER ALREADY EXISTS." I deleted settings for both and eventually deleted the whole pop and SMTP entries to no avail. I eventually deleted my entire Verizon account losing emails and address books. I made the outgoing servers the defaults for the email accounts e,g, Verizon, gmail, yahoo in various configurations to but to avail. I initially had this problem with THUNDERBIRD 78 though that eventually cured itself. Note emails set up as POP accounts. I have up to date Windows 10