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!

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

Send Message Error

  • 2 replies
  • 3 have this problem
  • 1 view
  • Last reply by jm57

more options

I'm unable to send any emails from account on Thunderbird. This just started this week. All send attempts generate this Send Message Error:

Sending of the message failed. An error occurred while sending mail. The mail server responded: Please turn on SMTP Authentication in your mail client. syn-076-088-235-065.res.spectrum.com ([192.168.1.25]) [76.88.235.65]:51343 is not permitted to relay through this server without authentication.. Please check the message recipient

This error for every recipient I typically correspond with. I have my same email account loaded into Outlook on another pc and I can send emails to all recipients without error from Outlook.

Help please.

I'm unable to send any emails from account on Thunderbird. This just started this week. All send attempts generate this Send Message Error: Sending of the message failed. An error occurred while sending mail. The mail server responded: Please turn on SMTP Authentication in your mail client. syn-076-088-235-065.res.spectrum.com ([192.168.1.25]) [76.88.235.65]:51343 is not permitted to relay through this server without authentication.. Please check the message recipient This error for every recipient I typically correspond with. I have my same email account loaded into Outlook on another pc and I can send emails to all recipients without error from Outlook. Help please.

Chosen solution

Did you turn on authentication? is the email address of sender the same as the email address in SMTP server settings? Would you please post a screenshot of the SMTP settings, and one of the server settings? That info may prove helpful.

Read this answer in context 👍 1

All Replies (2)

more options

Chosen Solution

Did you turn on authentication? is the email address of sender the same as the email address in SMTP server settings? Would you please post a screenshot of the SMTP settings, and one of the server settings? That info may prove helpful.

more options

My outgoing message security and authentication was off, I updated the authentication method, restarted Thunderbird and I'm sending messages again. Thank you very much!