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Hi , I am using the MacBook Pro M5 which is running with macOS Tahoe 26.5 . I have installed Thunderbird mail with version 150.0.2 . After the initial installation with only one account with few mails in the inbox I found the App opening time is abnormally high & is more than 1 minutes . I have removed the mail App few times & re installed it ( even I have re download the app from net again) , but the problem remain same .

I have removed the old folder & files from - ~/Library/Thunderbird/ , ~/Library/Application Support/Thunderbird/ , ~/Library/Caches/Thunderbird/ , org.mozilla.thunderbird from ~/Library/Preferences/. before the re installation & re started the laptop , but no improvement in results .

Also in mail setting references → Unchecked the option - Enable Global Search and Indexer Disable all Extensions and Themes under Tools → Add‑ons & Themes (No Extensions is installed) .

Just to inform that the apple mail is working fine in this laptop .

After all the above trails the results are same , the app once quit & re start - it takes around 1.5 minutes to open after which the app works normally with out any problem . Please suggest if any solution is available for this problem . Best Regards Gautam Banerjee

Lately, when I try to click on a different mailbox or message , nothing happens. repeating clicks sometimes works, and sometimes i have to first click on what I was previous viewing to get what I want to highlight, or click on different areas of a message or mailbox to get it to work. I am on mac tahoe 26.2. Did not have this problem before. What can I do to fix this problem?

Thanks Dan

It says that the folder is in use by some other operation. I tried a Force Quit and a restart and neither worked. Please help.

His OS is 10.13 and his TB is 115.18.0. He kept the old Mini because he was running an ancient version of Photoshop that ran a plugin that is not available for Adobe Creative Cloud.

Robert was a sculptor who did large kinetic work and much of his work is still on that computer.

I am still getting his email on my iPhone, so I don't know what is going on. Unfortunately, I haven't saved his email history on my iPhone so when someone answered a similar problem a couple of years ago, the only place that email would reside is in Robert's inbox on his Mini, which I can't open.

Many thanks for your help.

Ellen

The Inbox on my Thunderbird emails shows 224 messages but do not open. I have tried opening and deleting but to no avail.

IMPORTANTLY I am still receiving new emails.

I posted this question some time back but didn't receive any helpful answers and don't know where my post is. In the upper right-hand corner there is suppose to be 3 symbols. One to lower the app, one to make the app full screen or partial and one with an X. I have jumbled symbols where the 3 good ones are. It does it in trouble shoot mode. I tried disabling addons but I can't get the normal symbols back. Here's what it looks like... Thank you for any help.

Thunderbird has become crazy slow. 5-10 minutes to display an email. It's not my email server because my phone connects to and displays email fast. I have been through all the advice that I can find and cleared, checked, disabled everything that might slow it down. Still crazy slow. If I kill it and restart, I get about 3-4 minutes of reasonable performance and then it just stops. Latest Release Version V147.0.1.

i have a fast machine with 32Gb memory only 60% used, everything else runs fast

I don't want to junk Thunderbird, but it's unusable.

Help!

I have a Postfix/Dovecot server that hosts 10 of my domains from one IP.

When you open Thunderbird, it checks the domains you have preset. I have two. This happens immediately, especially if there is no new mail on the server. Everything works fine.

If you have other domain mailboxes open, and I have eight more, and you click the inbox on each one, Thunderbird stalls at the fifth mailbox, regardless of the inboxes' selected order.

tail -f /var/log/mail.log - confirms this.

I have reset or modified everything I can think of. My server is not throttling Dovecot.

This must be something internal to Thunderbird, possibly related to only using a specific mail server IP for all domains.

Google AI suggests assigning a unique local IP alias to each domain on my server so Thunderbird thinks it’s talking to 10 different machines. This seems extreme.

Any solutions?

For some time now, TB (147.0.1 (64-bit)) has been VERY slow loading, the first thing in the morning. If I close it and re-open, it opens at the normal--and desirable!--speed. Any thoughts? Regards, Dave

I've been using TB for years. Lately I can be browsing the Inbox when the contents will disappear and I get a message saying something like no messages found. After about 30 seconds the Inbox is displayed again.

TB never used to do this and it is similar to Firefox refreshing the screen which it also never used to do this.

Also how do I get from the Beta version to the standard version?

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?

Hi. I access a gmail account via Thunderbird. It's generally quite efficient, but recently it has become very sluggish. I have pretty fast internet, wired at 1G, so usually my mail appears almost immediately. In the last week or so it has slowed down dramatically, sometimes requiring multiple login attempts. Any idea what's going on? Thanks. Steve

Whenever I do anything with email I get a message "not responding" which causes a delay for a few minutes before it proceeds This occurs with almost every action Open email, delete email, browse a different folder (eg Inbox to Sent) it suddenly started happening yesterday

After an automatic update of my windows 11, the thunderbird has real perfomance problems! the program open very slow, it freeces permanently, that the program is not usable anymore. I have deleted Thunderbird and reinstalled but it still has the bad performance. Thunderbird on my Laptop with windows10 performance without a problem, is fast and does what it was designed for! What can I do??????????????

In a thread discussion about the flag, "browser.tabs.unloadOnLowMemory" dated 23-Nov-2022 (https://news.ycombinator.com/item?id=33706117) it was mentioned that we've disabled tab unloading on Linux because low-memory detection just didn't work.

Has the issue been fixed? Does the low-memory detection work in Linux? Can it be enabled now?

Does it get triggered when SWAP is being used? Or when system free RAM falls say to about 25% of total physical RAM?

Well, I just updated and still have the same problems. This browser is simply impossible to use; I can't even throw it away and forget about it: it can't load a single page without getting stuck halfway through, after which the app freezes and has to be interrupted, unloaded from memory, and only then (maybe) will the page load! It's been like this for six months now. It's probably time to ditch it completely!

What minimum memory spec is recommended for current Firefox usage? Have new computer with 16GB memory, 512 storage, intel core Ultra 5-225 processor & windows 11. Have not set it up yet.