How to resolve Slow Email Opening on macOS Monterey 12.4

Here is what worked for me today 6/26/22 (OS Monterey 12.4 on iMac). I went into Mail>Preferences>Privacy and unchecked "Protect Mail Activity." I made sure "Hide IP Address" was checked. Suddenly all my emails will open. It was taking 1-2 minutes or more every day since the last OS update. What a relief. I hope this is useful for you.

Hey, Mfiles, I know your email is close to two years old, but I can't thank you enough. Your simple solution worked! Now life is worth living again! Okay, that's a bit of hyperbole, but really: mega thanks.

olyman1955 wrote:

Seems like ever since my Mac OS Monterey was updated to 12.4, I've had a lot of problems opening my email. I can click on the email envelope to open my email and wait a minute or so for my emails to be downloaded. Then when I click on the email to open, it only opens to show who it's from and the subject, but it may take anywhere from 30 seconds to 2 minutes to fully open the message of the email. Even if it's only 2 or 3 lines. Normally, I could click on the email and it would open completely, whether it was an ad or a letter from someone. Has anyone else had this slow email opening problem?

Quit Mail. You can try holding the Shift key when you launch the Mail.app and see if there is a difference...

You can try disabling any mail plug-ins or extensions in Mail.app and compare your results...

Mail>Preferences>General>Plug-ins

You can try a SafeBoot of your machine as a test for some third party interference/cache clearing/ etc.

log in and test, reboot as normal and test

SafeBoot How to use safe mode on your Mac - Apple Support

I worked on this problem for 6 months on my Sister's old Mac mini. It was stuck on Monterey, and could no longer be upgraded. I think I did everything on the list including reinstalling the system. Nothing worked. Finally bought a whole new mini, imported all the old email and the problem vanished.

After spending a year trying every suggested solution to the slow Email downloading problem, I finally found the solution. I bought a new M3 iMac. Lightning fast now. It seems the problem was the old rotational hard drives on the Intel iMac.

Wow. Thanks Mfiles. I've been having the same problem in Sonoma 14.4 (maybe 14.3) and now 14.4.1.

Your solution of "I went into Mail>Preferences>Privacy and unchecked "Protect Mail Activity." I made sure "Hide IP Address" was checked." just worked for me too.

Thanks so much.

Thanks for the tip on copy/pasted text, should have thought of that...I removed all files in those two locations, restarted. Still same problem. Starting to think I might trying removing my two email accounts, then re-adding them, or more with a bunch more work, wipe, reinstall OS, then migrate back off my backup. Another thought just occurred to me, I do use BusyCal & BusyContacts, BusyContacts does interact with Apple Contacts, which of course is tied into Apple Mail. I wonder if anything causal could from those Apps? Could also just be a Bug in Monterey that Apple has no motivation to fix since support will drop this fall, or maybe they just don't know this is an issue...

Whenever I'm troubleshooting, I automatically dump the contents of Saved Application State.

I may try a new User Account tomorrow when I'm Fresh, or else first delete my email accounts then add back. I've since bought the Pro version of EntreCheck, can't beat it for $19. It alerted me to some old Apps, not likely related, some Canon files...but I have ditched all Cocktail files just in case. I'm suspicious I may just have a corrupted email in the mail datafile, I've been going in and stripping out attachments, so far no joy. Not gonna let it beat me though!

In Primary Admin, I removed the accounts restarted and added back, no change.

I logged out of Apple ID, no change.

I went into User Library and removed a bunch of preferences whose dates more or less coincided with the problem appearance, restarted, no change.

Next I removed the accounts, went into user Library and removed all files and folders with the name Mail, shut down, restarted, emptied trash. Added accounts back, all back to normal.

Wish I knew the specific cause, but that's unlikely to come to light.

Have you tried booting into Safe Mode as leroy douglas suggested in this first reply?

Boot into Safe Mode according to How to use safe mode on your Mac and test to see if the problem persists. Reboot normally and test again.

NOTE: Safe Mode boot can take up to 3 - 5 minutes as it's doing the following; 

• Verifies your startup disk and attempts to repair directory issues, if needed

• Loads only required kernel extensions (prevents 3rd party kernel/extensions from loading)

• Prevents Startup Items and Login Items from opening automatically

• Disables user-installed fonts 

• Deletes font caches, kernel cache, and other system cache files

If not then do so.

Have you tried the following: boot into Safe Mode according to How to use safe mode on your Mac and test to see if the problem persists. Reboot normally and test again.

NOTE: Safe Mode boot can take up to 3 - 5 minutes as it's doing the following; 

• Verifies your startup disk and attempts to repair directory issues, if needed

• Loads only required kernel extensions (prevents 3rd party kernel/extensions from loading)

• Prevents Startup Items and Login Items from opening automatically

• Disables user-installed fonts 

• Deletes font caches, kernel cache, and other system cache files

Thanks Old Toad; here it is

No major problems found

EtreCheck found no major problems with your computer.

Can I trust the Etre tool to get rid of some older files?

The old stuff relates mainly to adobe garbage (like everyone has) and some old printer related stuff.

generally to me it looks healthy (exept that the memory gets a lots of swaps) but performance even with Lightroom is OK.

First, there is no reason to ever install or run any 3rd party "cleaning", "optimizing", "speed-up", anti-virus, VPN or security apps on your Mac.  This user tip describes what you need to know and do in order to protect your Mac: Effective defenses against malware and other threats - Apple Community.  

There are no known viruses, i.e. self propagating, for Macs.  There are, however, adware and malware which require the user to install although unwittingly most of the time thru sneaky links, etc.   

Anti Virus developers try to group all types as viruses into their ad campaigns of fear.  They do a poor job of the detecting and isolating the adware and malware.  Since there are no viruses these apps use up a lot of system resources searching for what is non-existent and adversely affect system and app performance.

There is one app, Malwarebytes, which was developed by a long time contributor to these forums and a highly respected member of the computer security community, that is designed solely to seek out adware and known malware and remove it.  The free version is more than adequate for most users.  

That being said uninstall F-Secure according to the developer's instructions. Then rerun Etrecheck to make sure of the the F-Secure supporting files have been removed.

Another thing to remember is that you have the second slowest iMac sold by Apple at the time of purchase: 8 GB of RAM and a 5400 rpm drive in the Fusion drive.

Booting should be quick but opening and saving files on the HD will be a bottle neck.