Join the AMA (Ask Me Anything) with the Firefox leadership team to celebrate Firefox 20th anniversary and discuss Firefox’s future on Mozilla Connect. Mark your calendar on Thursday, November 14, 18:00 - 20:00 UTC!

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

can't send mails. error message: An error occurred while sending mail. The mail server responded: 5.7.1 Recipient address rejected: Authentication required.

  • 4 ردود
  • 10 have this problem
  • 1 view
  • آخر ردّ كتبه martindale

more options

thunderbird issue - can send mails fine from webmail, but not from Thunderbird. It's blocking all outgoing messages, and giving the error message: An error occurred while sending mail. The mail server responded: 5.7.1 Recipient address rejected: Authentication required.

Please check the message recipient....  

started suddenly - was working fine a couple of days ago. Any ideas?

thunderbird issue - can send mails fine from webmail, but not from Thunderbird. It's blocking all outgoing messages, and giving the error message: An error occurred while sending mail. The mail server responded: 5.7.1 Recipient address rejected: Authentication required. Please check the message recipient.... started suddenly - was working fine a couple of days ago. Any ideas?

الحل المُختار

Sending from webmail does not use SMTP server so trying to compare the 2 is meaningless. You need to find out what the correct SMTP server settings for your provider and make any needed changes. Wild guess is the authentication settings need updating.

Read this answer in context 👍 1

All Replies (4)

more options

You should talk to your email provider.

more options

Doesn't help unfortunately. I can send mails from webmail, so it has to be an issue in Thunderbird

more options

الحل المُختار

Sending from webmail does not use SMTP server so trying to compare the 2 is meaningless. You need to find out what the correct SMTP server settings for your provider and make any needed changes. Wild guess is the authentication settings need updating.

more options

changing settings to SML and different port fixed it