Why am I getting this error?
An error occurred while sending mail. The mail server responded: 5.7.1 Authentication is required to send mail as <sub1d1rdf@verizon.net>. Please verify that your email address is correct in your Mail preferences and try again.
Among other things, I have no idea who <sub1d1rdf@verizon.net is. </p>
Wšě wotmołwy (1)
Perhaps your email settings for incoming (pop 3?) and outgoing (smtp) are not correctly set. The Thunderbird site for setting up a mailbox can be found here:
https://support.mozilla.org/en-US/kb/manual-account-configuration
Authentication settings are among those also, and there are 5 different methods to choose from. Perhaps, yous is wrong in the settings?