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.

ابحث في الدعم

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

An error occurred while sending mail. The mail server responded: 5.1.2

  • 1 (رد واحد)
  • 2 have this problem
  • 18 views
  • آخر ردّ كتبه NicholasB54

more options

I have a center where two employees are using Thunderbird and they are the only ones getting this message. It just started today. No changes were made. The error is- An error occurred while sending mail: The mail server responded: 5.1.2 The address specified is not a valid RFC-5321 address. h81sm2028729ywc.40 - gsmtp.

I have verified all setting and verified the email address they are attempting to send to. They are able to recieve incoming mail but cannot reply. If they use gmail they can send and reply just fine.

Others in the center are using outlook at they are able to send just fine.

I have a center where two employees are using Thunderbird and they are the only ones getting this message. It just started today. No changes were made. The error is- An error occurred while sending mail: The mail server responded: 5.1.2 The address specified is not a valid RFC-5321 address. h81sm2028729ywc.40 - gsmtp. I have verified all setting and verified the email address they are attempting to send to. They are able to recieve incoming mail but cannot reply. If they use gmail they can send and reply just fine. Others in the center are using outlook at they are able to send just fine.

All Replies (1)

more options

Theres a lot of chatter about this over at the gmail support forum https://productforums.google.com/forum/#!msg/gmail/2tK2fR7yW-k/9Gk3L49QFCcJ

A couple of people finding solutions - worth a read .. but it's long. Not just Thunderbird affected, Outlook and several other clients too