Hello there Amcgall. We recieved Youre mail. We try To help you with it.

Greetings Firefox volunteer.

First, let’s take a quick look to confirm Mail really is the miscreant. Launch Activity Monitor (Command-Space and type Activity Monitor and it should launch immediately), and watch its data as you try to use Mail. Is Mail using too much memory? If the answer is ‘Yes’ then perhaps it’s time to try these strategies out:

Delete spam messages, delete deleted messages, delete messages you don’t need to keep and make sure your Computer is up to date with current system software.

How to reset Mail app using Settings :

Open Settings. Click on Apps. Click on Apps & features. Select the Mail and Calendar app from the list. Click the Advanced options link. Mail app Advanced options link. Click the Reset button. Reset Mail app on Windows 10. Click the Reset button again to confirm.

Install A good antivirus. it could be the problem.

mail us back after performing this.

We are here to solve questions

Greetings Firefox volunteer.

I'm not sure how much memory usage by Thunderbird you consider to be too much.

The amount of physical memory being used by Thunderbird is 335,476KB.

The amount of virtual memory used by Thunderbird is 285,476KB.

The amount of private memory (amount of memory in use by the process that can't be used by other processes) is 213,928KB.

My 64-bit Windows 10 Pro has 16GB of installed memory. Version 1709, build 16299.967. The CPU is an AMD FX-8350 64-bit, 8-core processor running at 4.0GHZ. My C: drive is an SSD with 122GB of free space remaining.

I'm using McAfee antivirus software.

I should also mention that I have archived mail going back to 2004. I do not want to delete it. I shouldn't have to if the app is written correctly.

Let me remind you that initially the app runs fast and normal. But over time it begins to slow down. I exit the app and re-load it. Then it's fast again for a while until it once again starts slowing down to a crawl.

Do the developers (the people who actually write the code for Thunderbird read this forum? I think their input is vital.

I'm using McAfee antivirus software.

This is your problem. I'd get rid of McAfee and stick to the built-in Windows Defender. Make sure to add the Thunderbird profile folder as an exception, so that it won't get scanned by the real-time anti-virus scanner.

Also see https://wiki.mozilla.org/Thunderbird:Testing:Antivirus_Related_Performance_Issues#McAfee

hello there again AMC gail.

a slow-moving computer that also becomes when you are on the internet is indeed worse than a broken computer.

If you're going to have any chance of reversing the serious slowdown that's affecting your computer, you're going to work out what's at the root of the sluggishness. identify the source of the problem with the help of these tools and tricks.

A good place to start is with the apps currently running on your machine and the ones that try and load themselves at the same time as your operating system. For that we need Task Manager on Windows. To see for Youre self.

A another way is.

do this, open your browser in “safe mode,” where it will load without any extensions at all. If your internetbrowser appears noticeably speedier in this mode, you’ll know that certain add-ons are bogging it down.

Then, it would just be a matter of disabling add-ons one-by-one in normal mode and seeing how much performance improves to pin down the problem add-ons.

at the same time a check of all updates on your computer machine to view and replace it for new is clearly also a good start.

I will hear from you after you have tried this.

We are here To help you. Greetings Firefox volunteer.

Let me make this clear. My computer is NOT slowing down. Thunderbird is slowing down. All other apps are loading and working perfectly.

In reply to another person: I certainly would never trust Windows Defender over McAfee antivirus. McAfee is not scanning my eMail files in realtime. I already checked that.

I certainly would never trust Windows Defender over McAfee antivirus.

It's entirely up to you to follow suggestions or not.

Try to start Windows in safe mode with networking enabled. - Win10 https://support.microsoft.com/en-us/help/12376/windows-10-start-your-pc-in-safe-mode

Still in Windows safe mode, start Thunderbird in safe mode. - https://support.mozilla.org/kb/safe-mode

Does the problem go away?

I kind of found a work around. If I run Thunderbird in Administrator mode the problem does not occur. Oddly enough my Windows 10 Pro account has Administrator privileges.

I have now right-clicked on thunderbird.exe, selected properties and clicked on the compatibility tab. I then checked Run the program as Administrator. Now when I load Thunderbird it will always run in Administrator mode.

I have know idea why this fixed the problem. But it did and I'm happy.

If I run Thunderbird in Administrator mode the problem does not occur.

I don't think this is a valid solution.

Oddly enough my Windows 10 Pro account has Administrator privileges.

It shouldn't be that way, and chances are that this will bite you at a later time. Good luck.

Christ1, you were right. Thunderbird still slowed down to a crawl even while running it in administrator mode.

So I'm back to square one.

Only way I can speed it up temporarily is to exit Thunderbird and then re-open it. Unfortunately, after a few minutes, Thunderbird slows to a crawl again.

I have email stored that go back to 2004. Literally hundreds of them. Maybe thousands. I prefer not to delete them. If the program is written correctly this should not cause the problem. I'm assuming ll of the emails are stored in some sort of database system.

I suggest you go way back to the post where you chose not to eliminate McAfee. It was a good product until John McAfee sold the company to others. The same can be said of Notons Anti virus. An excellent product until Symantec got their corporate hands on it.

Now both emphasize fear over fact and resource sucking security over a little education. Since 2011 I am actually doubtful McAfee have released a truly stable version of their product. It has been one disaster for their customers after another. It works I understand it if you only use a web browser and do nothing that deviates from web browsing, like accessing FTP site with the browser.

Thunderbird is slowing down because McAfee is fighting Thunderbird for access to the data files you are trying to use. They lost the plot back in 2011 and keep scanning the Thunderbird profile, on every file open and close and every download, mail deletion etc. I am sure you get the picture. I am not sure just how much of your SSDs life you want to give to useless and pointless scans. But I can almost guarantee a short and busy life for the SSD solely from the same files being read repeatedly.

I have no idea about access times on an SSD, but on a platter it takes an anti virus abut 10 minutes per GB to scan files. You say you have a large archive. So you probably have a very large global index file in your profile folder. Mine is around 4Gb and I consider my mail store fairly large. But on a normal day if I let the anti virus scan that file it would be a full time job. I get new mail about every 15 minutes (gmail is push so comes anytime) and the anti virus would be spending around 40 minutes scanning the file. That does not consider the fact Thunderbird has a single file per folder. So if you have messages in lots of folder and they are large this issue multiplies hugely in a short period.

Thunderbird stores mail in text files. NONE of those text files need to be scanned by an anti virus program EVER. Text files will not infect anything. They are inert. Even if they contain a dozen malware packages they are as inert as a lead pipe. So scanning wears out your drive, slows your software and produces exactly Zero improvement in security.

McAfee also comes with some ugly virus like tools that inject it into a running Thunderbird. That it is not compatible is not an issue, Thunderbird get crashed by McAfee so they can show off their glossy email tools that are rather hopeless really. And this forum, or others like it get yet another person with email client issues.

So if you insist on continuing with McAfee. It is your choice, you are their paying customer not me. I strongly suggest you create an exclusion in McAfee for the Thunderbird profile folder and disable any phishing, scam or spam filtering they offer. It usually results in lost mail and a crashed mail client. It might not be today, but they are no across installing an add-on in Thunderbird correctly and appear to not care that each new version of Thunderbird has new requirements for add-ons.

Interestingly they do not appear to play the same game with an outlook PST/OST file for some reason. Perhaps it is something about Thunderbird cross platform use of file extension, so McAfee can not decide what a file is because it has no file extension. I really don't know. But I truly wish they did, and did something about it.