Thunderbird Support Forum

Hello, The Optimum SMTP is recently rejecting emails I am sending from one of three Optimum email accounts that I have. When using the one account I get the following rejection notice:

Sending of the message failed. An error occurred while sending mail. The mail server responded: Spam detected by content scanner. Message rejected (ID 6661A65F0037E564). Please check the message and try again.

This only occurs when I use Thunderbird to send messages. If I use Outlook on the same computer, I do not get the error. Previously, I was getting the error on all three accounts, but when I upgraded to 64-bit Thunderbird, the problem went away. Of course, I called Optimum and they said that the problem was on my side and were not helpful. They also don't take any responsibility if you don't use their web interface.

I would appreciate any ideas that anyone has on what I could try to eliminate this problem. Thank you.

For the Inbox (main) window:

• Choosing File::Close does nothing.
• Typing Cmd-W flashes the title of the File menu but otherwise does nothing.
• The only way to close the window is to click its red close button (upper left).

Thunderbird 116.0, 115.10, 115.08 and earlier Mac OS 114.5 and earlier

For the past several years I have been dealing with Thunderbird occasionally freezing on me, with the window losing focus and the titlebar saying (Not Responding).

It appears to happen when TB is downloading email. If the emails are large (as some are) TB stops everything to deal with it. I have looked for where to change any settings to allow for process threading, since that was the promise of Windows waaaaay back in 1990. Not so, apparently with TB. Even if I'm in a separate window composing an email, it freezes. I wrote about this back in 2018...

https://support.mozilla.org/en-US/questions/1233121

I noticed that this only happens when downloading emails from one particular account, which I use for receiving project code error debug reports. The emails are typically around 150k or slightly less. Not so huge that it should take so long to pull down, but the debug info is in many, many nested tables and divs. Is it trying to render them, even though I don't have them open?

In any case, I set that account to no longer collect. Yet, every once in a while, it still collects. Do I need to remove the account from TB altogether? I would like to be able to have this account checked every 15 minutes like my other five email accounts, which don't cause me any heartache, but it's driving me mad, especially when a throng of those emails come in, like 50 at a time, and I am effectively prevented from doing anything in TB for up to five minutes. I suppose I could craft the emails to be smaller (it's my own code that is sending the debug reports) but the info in there is there on purpose.

Is there a setting I can change somewhere to break off the processing for the main window and the compose windows?

Good afternoon I have 2 accounts in Thunderbird - a gmail and a Yahoo. Both were running great from the time I set up Thunderbird about 2 weeks ago until yesterday when the gmail account stopped sending and receiving. The Yahoo account is still fine. I have not received a message in Thunderbird in my gmail account since, although I have logged in on the web and confirmed that there are incoming messages in my account.

When I attempt to send a message from the gmail account I receive an error message - "Add Security Exception". If I click "View" nothing happens. If I click "Get Certificate" the section "Unknown Identity" changes to "No Information Available". However, when I cancelled the message I noticed a new error message appeared - "Send Error Message" and when I returned to the main Thunderbird screen I noticed a new tab appeared "Certificate for smtp.gmail.com".

As you can imagine, I seem to be getting nowhere with this and as I am only an intermediate user with computers I don't know where to go next. Subsequently, I sincerely hope that someone out there is able to help me. Any assistance would be very much appreciated.

The following are my Thunderbird settings for the gmail account :- Incoming Server Server type : IMAP Mail Server Server name : imap.gmail.com Port : 993 User name : [myname]@gmail.com Connection security : SSL/TLS Authentication method : OAuth2

Outgoing server Description : Google Mail Server name : smtp.gmail.com Port : 465 Connection security : SSL/TLS Authentication method : OAuth2 User name : [myname]@gmail.com

A copy of the error messages as well as the Certificate are attached.

I ran into an error on my Windows 11 PC. If I add an attachment via the system menu called up by the right mouse button, the size of the attachment is displayed in terabits and cannot be sent :-)

All messages that I delete,send ,archive and drafts, simply disappear without a trace.For years this worked well !Tried downloading and reinstalling Thuderbird without success.

I've just started getting error messages that I need to enter my password to send emails. I've tried that but it still keeps saying unable to connect to the server. This has been happening for about two days now. I've tried updating Thunderbird, restarting Thunderbird and restarting my PC. None of this has worked. I made no changes to my system, software or home network. Any help would be appreciated. Thanks, Dave

I have several Comcast.net accounts that I have set up in Thunderbird. About 2-3 times per week, Thunderbird makes me re-enter one or more of my passwords, only for the comcast accounts. It says Authentication Failure, but I have not changed anything on the accounts, including passwords. Entering the same password works - for a while. Any idea how to stop this?

On startup TB pops an error box up saying ' There is no email program associated to perform this action'. When dismissed TB continues to open normally. No other errors seen during operation.

I have checked my Win 10 Control Panel Apps options. TB is the email default. MailTo, file type .eml and all other settings I can see are set to TB as well.

Hi I have asked a question about my new email account in outlook. I have set up a new identity with the new email address. I have set up an app in outlook. I can receive emails but cannot send them. Answer have apparently been posted but I can’t see the email thread either. I really need some help here please. Can the answer be emailed to me or at least a link to where the answer is posted on the thread. Thanks

Hello! Since I couldn't find help in the forums, I will create a new question. For about a year now the PC at my work will not open mailto-links correctly. There is no account to select from, the subject has a lock-symbol. The receiver's address is correct though (I replaced it with "address" for the screenshot). This PC is the only one I know with that problem and only with external mailto-links. If I click on an email address inside a mail, it opens it correctly. Thunderbird version 115.11.1 (32-Bit), Win 10

It's pretty impractical, so I am hoping for help. Thank you!

When going from Help on menu to check for updates receive the error message - Failed to check for updates.

Running on Windows 10 with NAV - problem is recent in origin but I can't be exact as it's not my regular PC.

So far I've manually updated Thunderbird from 115.11.1 to 115.11.2 (64bit)by downloading from Mozilla website, rebooted from cold several times, and applied the fix from Norton:" https://community.norton.com/en/forums/auto-update-norton-360-v2449067835-now-causes-security-exception-thunderbird " in case it was related. It appears to be unrelated because on my regular PC the NAV update occurred necessitating the fix to the security exception error but don't have the checking for updates error.

thanks

Suddenly without warning Thunderbird displays a message 'Checking mail server capabilities.......' in the bottom left of the inbox screen. Messages from the server [Optus] are not downloaded. I have changed the SMTP server to the default 465 and changed the security setting to 'None' but the problem has not been resolved. I note that there are alot of queries about this problem but I cann ot find a solution anywhere on the Mozilla help pages.

Hi. I was receiving emails until 10:30am yesterday and then nothing. No emails are being received on any of my email addresses since then on my Thunderbird site. I can receive them on my phone, so I know I am being sent emails but nothing on my computer. When I click "Get Message", nothing happens. When I try to send a email - "Add Security Exception" screen comes up saying you are about to override how Thunderbird identifies this site. Why has this just started and what do I need to do to be able to receive and send emails again?