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.

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.

Rohkem teavet

Thunderbird doesn't synchronize after Windows update

  • 5 vastust
  • 1 on selline probleem
  • 13 views
  • Viimati vastas Toad-Hall

more options

Hi all,

Yesterday I did Windows update and now my Thunderbird doesn't download e-mails, I can't send anything either.

I run Win 10 Home, 1709, 16299.125

I have 4 accounts on my Thunderbird, different mail providers, none of them work. I deleted accounts and tried to create new one and when providing details for Gmail it says: "Configuration could not be verified - is the username or password wrong?" So at the moment I'm even unable to add an account.

I run NOD32 - I disabled it for test, same results. I added Defender firewall outbound and inbound rules for test, same results.

Any thoughts for fix??

Hi all, Yesterday I did Windows update and now my Thunderbird doesn't download e-mails, I can't send anything either. I run Win 10 Home, 1709, 16299.125 I have 4 accounts on my Thunderbird, different mail providers, none of them work. I deleted accounts and tried to create new one and when providing details for Gmail it says: "Configuration could not be verified - is the username or password wrong?" So at the moment I'm even unable to add an account. I run NOD32 - I disabled it for test, same results. I added Defender firewall outbound and inbound rules for test, same results. Any thoughts for fix??

All Replies (5)

more options

I deleted Thunderbird fully (including \AppData\Roaming\Thunderbird folder) and I managed to create accounts and it's working now,

However I had issues with certificates, said it's untrusted certificates. Also my Firefox had issues with certificates yesterday.

Would you know how to fix it?

more options

Exactly what the certificates say and what the issue is is vital in this sort of query. Could be anything from some sort of parental control to your device being hacked.

more options

Unfortunately it's not working again, same thing happened.

Thunderbird doesn't download any e-mails....

Please help

more options

Outlook doesn't connect with servers either ;/

switched off antivirus and firewall - same issue spoke to ISP - they confirmed required ports are open and there are no issues

more options

If nothing is getting through no matter what account, check that Thunderbird is an allowed application in the Windows defender Firewall.

Disabling the 'Windows Security Center' service will not disable Windows Defender AV or Windows Defender Firewall. These will be disabled automatically when a third-party antivirus or firewall product is installed and kept up to date.

Please confirm you are not using another AV product eg: Norton, AVG etc

Use the info at the following link to set up Thunderbird as ana llowed program. https://www.tenforums.com/tutorials/70903-add-remove-allowed-apps-through-windows-firewall-windows-10-a.html

Exit Thunderbird. Access Windows Defender Firewall. (Assuming you are not using any other installed AV product) Set Thunderbird as an allowed program. If it is already selected, then block Thunderbird, ok it and then access again and reset to 'Allowed'.

Confirm you have setup Thunderbird as an allowed program.