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

Thunderbird receives email but won't send email

  • 3 tontu
  • 3 am na jafe-jafe bii
  • 1 view
  • i mujjee tontu mooy lifeorigin

more options

A few weeks ago Thunderbird stopped allowing me to send emails. New emails I receive download fine. Here is the error message I'm getting:

An error occurred while sending mail. The mail server responded: 550 5.1.0 Authentication required. Please verify that your email address is correct in your account settings and try again.

I've checked that my email address is correct and that my outgoing server is smtp.comcast.net but that is the extent of my knowledge of what I can check. I hadn't changed any settings and this just started happening.

Help would be very appreciated! Thanks in advance! Linda

A few weeks ago Thunderbird stopped allowing me to send emails. New emails I receive download fine. Here is the error message I'm getting: ''An error occurred while sending mail. The mail server responded: 550 5.1.0 Authentication required. Please verify that your email address is correct in your account settings and try again.'' I've checked that my email address is correct and that my outgoing server is smtp.comcast.net but that is the extent of my knowledge of what I can check. I hadn't changed any settings and this just started happening. Help would be very appreciated! Thanks in advance! Linda

Saafara biñ tànn

You can check that the SMTP authentication is set to normal password, the error message indicates it is set to none and that is not acceptable to comcast.

Jàng tontu lii ci fi mu bokk 👍 1

All Replies (3)

more options

Saafara yiñ Tànn

You can check that the SMTP authentication is set to normal password, the error message indicates it is set to none and that is not acceptable to comcast.

more options

Thanks you so much, Matt. Problem solved!

more options

My verizon.net email goes through AOL.com I have all the right settings confirmed by AOL.com technicans. Thunderbird sometimes sends emails, and sometimes won't, almost daily.

They say Thunderbird is the problem.