Were these accounts working (able to send messages) before but have now failed, or are these newly created accounts in Thunderbird? This has NOT effected the inability to send smtp mail (I just tried, again!) I CLICK ON 'CORRECT' AND IT SENDS THIS POST. Ps RECENTLY WHEN TRYING TO POST THIS MESSAGE I GET A POP UP WINDOW YOUR TCP SETTINGS ARE NOT COMPATIBLE WITH YOUR ROUTER. (including OS or Thunderbird updates, adding extensions or themes, etc. * Any recent changes in your computer or software configuration that might be relevant? + Tools>Account Settings>Outgoing Server (SMTP) (at the bottom of the list of accounts on the left)>*server*>Edit? * Without divulging your e-mail address or account name, what are your server settings, including server name and port number for:

Check for more information on compacting folders. * Do you regularly compact your folders? Weekly or more often is strongly recommended. * What is the EXACT wording of the error message that you are receiving? * Were these accounts working (able to send messages) before but have now failed, or are these newly created accounts in Thunderbird? * Which version of Thunderbird? Check Help>About for the version number.

Yahoo smtp not working on thunderbird