This site will have limited functionality while we undergo maintenance to improve your experience. If an article doesn't solve your issue and you want to ask a question, we have our support community waiting to help you at @FirefoxSupport on Twitter and/r/firefox on Reddit.

Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

Why am I getting this error?

  • 1 reply
  • 1 has this problem
  • 1 view
  • Last reply by Bob

more options

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>

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.

All Replies (1)

more options

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?