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Hi! I am trying to use the Thunderbird application to help me view a huge '.mbox' file from an email account that is no longer active. I have the entire file saved to my computer as I downloaded it before the account was closed. Can you help me access those files? I am working on a huge project and really need to look for date sand times of emails sent in the mailbox so that i can piece together the timeline of the project. I would greatly appreciate this!!!

My old email server was Mediacom (mchsi.com). I had that email account plus a gmail account on Thunderbird. Sometimes people said their emails to my gmail account would bounce. I changed email servers and no longer have the mchsi.com email or Mediacom server and have 2 gmail accounts on Thunderbird. The new one works fine. When I send an email to the old gmail account it bounces back saying "address not found. Your message wasn't delivered to ------@mchsi.com because the address could not be found or is unable to receive mail. 550 5.1.1 I had the tech that sold me the PC look at the settings on Thunderbird for the gmail account and he said they were okay. Where else can he check? Somehow the pc thinks that just that one gmail account is run through or attached to mchsi.com Kathy foggiak@gmail.com

1. I've drafted an email, then hit save / closed the email and opted to "save changes". 2. I try to edit that email, but it is just "flashing" in the preview screen. I right click on it to "edit draft message", but that just brings up a blank email. 3. The status in the bottom left of the screen shows "loading message..." "downloading message", repeatedly. 4. It was working fine earlier in the week, but Thunderbird Desktop Version 140.7.0esr | Released January 13, 2026, seems to be when the problem started?

Just installed TB 147 under Windows.

Previously, there was a menu item File/Compact Folders (plural).

It is now (at least on my machine) replaced with File/Compact Folder (singular), which only compacts the currently active folder. I cannot now find a way to compact all folders at once.

What am I missing?

I've read this is a common issue but hoping maybe things have changed? Trying to make a filter that says move to the junk folder email where subject starts [SPAM] (the hosting service adds that) UNLESS the address is in an address book, BUT I also need to accept everything from numerous domains. I see work arounds "if the address ends in @somedomain.com" but then I'd have to do that for every domain I want to receive from. Any email from any address where I have put *@domain.com in my address book should be let through. But I know TB doesn't accept wild cards in the address book. There MUST be some way around this? Thanks.

Hi there, since recently, I encounter the following error message when trying to send emails via Thunderbird on my mobile: Failed to send some messages. Requested action not taken: mailbox unavailable DNS MX or A/AAAA resource record 1MgvvT...

The SMTP server settings are as shown on the attached screenshot. I haven't changed them since installing Thunderbird and the problem appears for the first time. Thunderbird version is 15.0.

Is there anything I can do about it, e.g. by changing my Thunderbird settings? Since gmx.net is a webmailing service, I cannot change their server configuration. Any help is highly appreciated. Thanks a lot to all of you!

I am trying to send emails from a software program through Mozilla to individual customers. I am receiving an error message. "Mailbox unavailable. The server response was: 5.7.1 Message detected as spam. [1768849024-673587]." Can you help??

On Monday, 17 November 2025 the Security Certificate expired and I stopped receiving emails both on my computer and Andriod Device. As a result I am not receiving any emails through Thunderbird, but I can go to email host site to view them.

I logged in my computer tonight and clicked here and clicked there and the error message: "The certificate for mail.homebizmall.net is not valid for that server. Someone could be trying to impersonate the server. Create an exception but this could mean that someone has stolen your certificate and may be able to impersonate you."

So it seems the POP server and the SMTP server certificates were only valid for 3 months and I was FORCED to create the exception for both servers. Now I am worried the security has been breached.

By clicking here and clicking there, I stumbled on a few people who seem to have this problem, but each with their own limitations. My operating System is Windows 10 without the option to upgrade. I have not extended the security updates because I don't understand if it is just the operating system uploading to the cloud or everything on my computer and I am not prepared to do the latter.

Is it safe to leave the band aid on that I have used for the moment? Can I create an exception for the phone? Or is there a glitch that someone needs to walk me through fixing?

Thanking you in advance

Clinton

I have just installed Thunderbird for my wife on Fedora. She is struggling because she relies on her program (formerly mac Mail) 'knowing' the addresses of contacts and autosuggesting when she types the first few letters. Obviously with a fresh install of TB, it doesn't 'know' any of her contacts. Is there a way to make it learn from the Sent Items folder? So that it auto adds all addresses she HAS SENT TO (in the past), to her contacts/address book? Thanks

Hi, I'm following up on this thread which is closed- https://support.mozilla.org/bm/questions/1483264 It describes an add-on: "DefaultColumns" https://www.ggbs.de/extensions/#dc. I could not find verification of safety for this add-on. I reluctantly installed but it wants permission to my whole computer so I uninstalled.

To me, this functionality is a necessary feature needed in Thunderbird. It merely creates default columns for all new subfolders. Could someone verify the safety of this add-on, recommend a safe option or add the functionality to Thunderbird. Thanks.

good day....ii hope someone can help. the other day i was accessing my yahoo account spam folder and by accident, i deleted the spam folder instead of emptying it. the spam folder is now sitting in the trash and i'm unable to remove it from there. when i log into my actual yahoo account, the spam folder is where it's supposed to be and not in the trash. i tried removing the yahoo account from thunderbird and reinstalling it in hopes that it would rectify the problem, but it hasn't. does anyone have a solution?? i would greatly appreciate any help you can offer. thank you for your time...mike s

The File (saving to a folder) Recent function used to have the folders alphabetically. Some genius thought to reorganize the Recent folders to be in chronological order. Is there a setting to have the Recent folders be in alphabetical order again? I could not find anything. Thanks in advance.

Unable to add my Mailfence email account to Thunderbird deb install on Ubuntu 24.04.3 Set Up Your Existing Email Address in Thunderbird returns " Thunderbird failed to find the settings for your email account" yet my web mailfence is accessible

Hello, I am wondering why mail that is 'Junk' and appears in my 'InBox' rightfully marked as such, still shows up, in my "InBox". Why doesn't it immediately get transferred to the 'Junk' Folder, like it use to? Or is there now something that else I have to do, after marking it as 'Junk'? In time past, as soon as I marked an item as 'Junk' it would transfer to the 'Junk' folder immediately. Why does this no longer happen?

When I accessed TB it updated to an ESR (Eclipse) version and when I load it I get a message saying I've used an old version, would I like to create a new profile. ( I didn't) I've copied my backup to the profile but many folders are missing from the current profile.

How do I get all my folders to display? I've reinstalled TB version 147 without the ESR option.

1. I am getting Mozilla Thunderbird ESR notices pop up when I log on to my PC (W11). I checked my Thunderbird version and I have 146.0.1 and I am on the release channel so why am I getting these notices ? 2. Recently I noticed that when I try to move e-mail messages to a specific folder, I right click on the message and get the prompt Move To and then Recent Destinations where the problem exists. The list of Recent Destinations used to be in alphabetical order and now it is sorted by most recent destination time. This slows me down considerably. Please revert. Thanks !!