Thunderbird Support Forum

I have tried nearly everything on all the forums and help sites to no avail. I still get the error message that my message cannot be sent. Most of the time I get the server response as [C20]: message blocked. I have triple-checked my SMTP server settings and password, uninstalled TB and re-installed. TB seems to have recently changed the profile in use, so it no longer has all the files in Mail\Local Folders it used to have. I'm thinking I need to create a new profile but I don't know how to do that.

Hello,

My boss, (small family business) insists on using Thunderbird for the business. He sends and receives hundreds of emails every day. Often times has 20+ email tabs open at the same time. It's become such a problem that I have purchase larger SSD drive because he was always running out of storage space on his PC. His Thunderbird file is currently over 12 gig.

The main issue is: He will have several emails open and will start to reply to a customer. When he hits reply, the body of the email references data from an really OLD previous email that was either archived or deleted. Most of the time these are emails that were previously deleted. Then he goes back to his Inbox to try to find the original message and it cannot be found and is missing. He then finds the original email on his iPhone Inbox (Same Email Account - IMAPED to his phone) then forwards it to himself, in order to obtain the original contents of the message again. Sometimes the reply box has data from multiple old emails! It's hard to explain.

This goes on and on and he's driving me nuts, as I'm the local "Mr. IT Fix it." for the company. Although, I have no formal degree or training in such things. My background is in Accounting. LOL

From reading other forums, this appears to be either an IMAP Indexing or Email Deletion Retention policy issue? But it's just really beyond me!

Both myself and a family friend who actually has IT support exp. have told him to stop using Thunderbird for Enterprise use, and migrate to a more appropriate application. But he doesn't want to have to learn anything new or complicated.

Any thoughts, suggestions, other places where I can find a possible solution?

One other thought: This issue does goes go away (albeit Temporary) when I clear his system cache and Force ALL Thunderbird folders to Compact. Thank you!

If the above data is too vague, I can try to provide steps to replicate and screenshots on the next time this happens. Which is often. However, it is almost impossible to replicate on demand.

Additionally - I've read in other forums of similar issues where they were related to indexing and IMAP syncing across multiple devices. One person commented - that it was a deletion retention failure policy within Thunderbird. Something to the effect of, Thunderbird never really deletes emails when you press delete on the desktop application. The email is marked for deletion but all of the email headers and data is still stored in the active cache, or something like that. - And apparently, there is a lag in time that the server or servers update a deletion request if the email is deleted from another app. His primary email host is Comcast.net. So, he's using Comcast Webmail, Thunderbird Desktop, and iPhone 13 mail app. via IMAP, all for the same account that has about 10+gig of stored emails. Oh, he currently has threads turned off by request. Storage cache is currently set to 650mb.

Any help, suggestions or solutions are greatly appreciated. If you have any areas that need clarifying, I would be happy to take screen shots or provide additional data in order to find a valid resolution, as he's not interested in migrating to Outlook or any other Enterprise application.

Thank you!

Witam, w ostatnim czasie mieliśmy jakiś spam na naszą pocztę i dostaliśmy blokadę, zależy nam na zdjęciu jej ponieważ jest to e-mail firmowy i jest nam potrzebny. Proszę o informację co mamy zrobić aby zdjęto blokadę. Pozdrawiam

Hello everyone. I have just installed version 115.11.1 (64 bits) on my PC. The fonts of the incoming mail messages display strangely and change when I move the mouse over them. Attached are two screenshots of the same messages at two different times: https://mega.nz/file/vZtlBCSa#Hi_C1bjz4NNvG5WPfqSam1eefv7BHvF4bGv6VWNDZ8g

The rest of the programs and windows display normally. The problem only exists in Thunderbird windows. Does anyone have any idea what the problem is? Could a graphics card at the end of its life be at the root of the problem? Thanks.

Witam, Mam problem z wysyłaniem wiadomości przez Thunderbird. Przy próbie wysłania wyskakuje takowy komunikat. Nie rozumiem z jakiego powodu mogłem dostać blokadę, ponieważ nie wysyłam aż tylu wiadomości, żeby można je było uznać za spam. Co mogę zrobić w takiej sytuacji, aby jak najszybciej odblokować swoje konto? Proszę o jak najszybszą pomoc, możliwość wysyłania wiadomości jest mi bardzo potrzebna. Pozdrawiam.

I have been trying to send a couple of emails today and I keep getting a server error message. I am not good at all with computers . I am a 78 year old partially disabled vet with no computer knowledge. My son set this up for me years ago but he has since moved away. I sent one email this morning that went out but now nothing works. I think I can receive emails but not sure now.

Dear community,

I use a MacBook Air (software version 13.6.1 (22G313)) and Thunderbird as my mail client (software version 115.11.1 (64-bit)).

I have set up approx. 8 mail accounts, but for a few weeks now I have had the problem with my google mail accounts that mail with somewhat larger attachments (approx. 5MB) is often (not always) sent, but no copy is saved in the Sent folder.

I get the following error message from Thunderbird:

The message was sent, but no copy was saved in the Sent folder because there were problems accessing the network or files (translated from German, original English error message may differ slightly)

Security and authentication settings of the affected IMAP and SMTP accounts:

SSL/TLS OAuth2

Changing these settings was not successful, sending mail was no longer possible with other security settings.

A request to google support did not help, I was referred to Thunderbird support.

Perhaps someone has an idea for me as to what the problem could be?

Thanks a lot and a nice day to you all! Hendrik

I keep getting the message that TB can't connect to my server. I am able to go to my server in a Browser window, I have re-entered the password Multiple Times and it still will not connect. What else can I look at? Tony

Thunderbird has for the past few days begun giving me this error message every time I lick into your program. "Login to server imap.gmail.com with username rg.mccormick43@gmail.com failed". I am also recieving this message for aol.com.

Interestingly, gmail messages continue to come into the program but I cannot send any messages. Unless this is fixed quickly I will drop your program and go back to using google, which I hate, for my email program.

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?

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 :-)

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.

We have had thunder foe a few weeks now and have been very happy with it. Today it suddenly stopped sending and receiving emails. I have checked the help page but am struggling to figure out how to fix. Can you please help. Cheers Colin

I just started using TB about 2 weeks ago. I have not even gotten to the point of installing a eml to mbox software to move my folders, etc into TB from emClient. I am changing because emC quit authenticating 'out of the blue'. I have been getting and sending emails perfectly well in TB until about 4 days ago. I get a message that says it cannot connect to Comcast server. Nothing about authentication or a password. It just stopped! I talked to Comcast tech support today and they said everything on their end looked good. I have spent several hours tonight going thru TB checking everything, reading this forums notes on unable to connect, restarted a couple of times, etc. Needless to say, I am not happy and really don't know if I should ditch TB and go to a 3rd different email program. (Note: I am not one who changes often or without a fight to keep a program.) I have been with emClient for over 10 yrs. All their suggestions have not worked. I like TB and really want it to work. Suggestions please.

Today, Thunderbird has switched servers on my two email accounts. My two accounts are a Cox email which has been moved over to Yahoo and a business account which uses Gmail. I have messages on the Yahoo server but when I ask Thunderbird to "Get Messages", I can see from the info at the bottom of the screen that it's checking Gmail not Yahoo.

Okay, all of a sudden it's now back on track. I don't understand how this glitch came about. Hopefully, it won't happen again.

Bill Dinger

Dear Sirs,

Please help why didn’t support China Office 365? We are using China exchange online, but it can’t use Thunderbird login our account. We have ask them, they need the software register to their system, could you register thunderbird to their system? Thanks!

Kin

How do I get Thunderbird working again? (Out since 30.05.24) I am a senior and need easy directions to follow as not tec. savvy. I was an iinet customer - now themessaging.co