I have nine different email accounts on sbcglobal.net. Since upgrading to Thunderbird 78, three of the accounts I cannot receive or send emails. I have checked the account settings on each one and they all the same. I get an "Error with account XXX" box that says "Sending of password for user XXX@sbcglobal.net did not succeed. Mail server inbound.att.net responded: Server error - Please try again later." for those three accounts when i open Thunderbird or try to get new messages. If I try to send an email from one of those accounts I get an "Alert" message box that says "An error occurred while sending mail. The mail server responded: Request failed; Mailbox unavailable. Please verify that your email address is correct in your account settings and try again." I can access each account thru Firefox with out any problems, so I know the email addresses and passwords are correct. I have been pulling my hair out trying to figure this out. Any suggestions? H E L P