Windows 10 reached EOS (end of support) on October 14, 2025. If you are on Windows 10, see this article.

Avatar for Username

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
This thread was archived. Please ask a new question if you need help.
Archived

connecting to Outgoing server (SMTP) smtp.gmail.com failed

Thunderbird Connectivity
Wman replied
Wman
Wman

Since more than a week I encounter problems in sending emails (receiving emails works fine). I always get following message: "connecting to Outgoing server (SMTP) smtp.gmail.com failed". So i finally uninstalled Thunderbird, and re-installed it this morning. But the issue remains. Windows 11 Thunderbird version 128.9.2esr (64 bit) outgoing server settings: server name: smtp.gmail.com, port 465, Authentication method: OAuth2, Connection security: SSL/TLS.

From what i gather, i dont seem to be the only one who is experiencing these problems recently. Please help?

Since more than a week I encounter problems in sending emails (receiving emails works fine). I always get following message: "connecting to Outgoing server (SMTP) smtp.gmail.com failed". So i finally uninstalled Thunderbird, and re-installed it this morning. But the issue remains. Windows 11 Thunderbird version 128.9.2esr (64 bit) outgoing server settings: server name: smtp.gmail.com, port 465, Authentication method: OAuth2, Connection security: SSL/TLS. From what i gather, i dont seem to be the only one who is experiencing these problems recently. Please help?

All Replies (1)

Wman
Wman Question owner

I finally found the culprit, and I was able to solve the issue after 2 weeks of frustration... Change the outgoing server settings as follows: change the Port to 587 (instead of 465) and change the Connection Security to STARTTLS (instead of SSL/TLS). Restart Thunderbird, and the issue is sorted.