Mozilla Monitor website will be down for 2 hours starting 5/20/2025 at 6 AM PT. Visit our status site for updates.

Avatar for Username

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 closed and archived. Please ask a new question if you need help.

GMAIL SMTP stopped working - Won't send at all.

  • 5 replies
  • 1 has this problem
  • 1599 views
  • Last reply by SuMo Bot

SuMo Bot
SuMo Bot

WIN7 Starlink Internet Latest version of Thunderbird


Thunderbird stopped being able to send all of a sudden through gmail. I can receive messages fine. I keep getting an error about timing out on SMTP server. All server settings are correct per gmail's outgoing server page. It was working for a few minutes last night after hours of messing around with this issue then stopped again. I've installed another client and it worked for about an hour then stopped being able to send as well.

Things I've done: Delete profile (kept messages) - setup email again Uninstalled and reinstalled TB Completely disabled antivirus Increased time out in TB settings

Settings: smtp.gmail.com port 587 (tried 465 as well) Connection security: SSL/TLS Authentication: OAuth2

Driving me nuts because this is for my business and have to send emails through the gmail webpage.

Thanks for any direction!

WIN7 Starlink Internet Latest version of Thunderbird Thunderbird stopped being able to send all of a sudden through gmail. I can receive messages fine. I keep getting an error about timing out on SMTP server. All server settings are correct per gmail's outgoing server page. It was working for a few minutes last night after hours of messing around with this issue then stopped again. I've installed another client and it worked for about an hour then stopped being able to send as well. Things I've done: Delete profile (kept messages) - setup email again Uninstalled and reinstalled TB Completely disabled antivirus Increased time out in TB settings Settings: smtp.gmail.com port 587 (tried 465 as well) Connection security: SSL/TLS Authentication: OAuth2 Driving me nuts because this is for my business and have to send emails through the gmail webpage. Thanks for any direction!

Chosen solution

The gmail outgoing server works on port 465, SSL/TLS, or 587, STARTTLS.

Timeouts are often due to antivirus. You must run Windows in safe mode to eliminate possible interference by AV ('disabling' isn't sufficient), or remove it temporarily. A VPN can also interfere, if you have one.

Read this answer in context 👍 0

All Replies (6)

SuMo Bot
SuMo Bot Question owner

Error message is: The message could not be sent because the connection to Outgoing server (SMTP) smtp.gmail.com timed out. Try again.

sfhowes
sfhowes
  • Top 25 Contributor

Chosen Solution

The gmail outgoing server works on port 465, SSL/TLS, or 587, STARTTLS.

Timeouts are often due to antivirus. You must run Windows in safe mode to eliminate possible interference by AV ('disabling' isn't sufficient), or remove it temporarily. A VPN can also interfere, if you have one.

SuMo Bot
SuMo Bot Question owner

Thanks! It worked in safe mode so I'm thinking I'll check into Avast antivirus and see if there's anything that would block it. If not I could just uninstall and see if it clears up then I'll know for sure it's an AV issue.

I appreciate the help -at least I have some hope now. :-)

sfhowes
sfhowes
  • Top 25 Contributor

Avast/AVG are well-known sources of trouble. Disabling Mail Shield might be sufficient:

https://support.avast.com/en-ca/article/antivirus-shield-settings/#pc

SuMo Bot
SuMo Bot Question owner

Thank you very much!

SuMo Bot
SuMo Bot Question owner

This question has been locked because the original author has deleted their account. While you can no longer post new replies, the existing content remains available for reference.