Mail very slow in Mountain Lion

I have the same problem. Besides this most of the time when my imac is awaken from sleep mail hangs and I see a crash report. I have send it to Apple support several times.

So my problem with mail is on my imac.

I have a MacBook Pro and a MacPro and both are giving me the same problem with mail after I upgraded to Mountain Lion.

It take ages for mail to start when I start the program for the first time. Attacments are not shown in the mail and I am unable to complete a message. I have to save it as a draft first, the open it again and then the attachents are vissible. Only then can I reply to the mail.

This is very bad! I wish I never did the upgrade :-(

I really hope that apple will fix this ASAP.

I too experience problems with the Mail app after upgrading to Mountain Lion. My p[roblems are not quite as severe but still annoying enough to make working with Mail a pain:

I can open Mail as quickly as before but when I select a message or switch between inboxes (icloud and two IMAP accounts) the response is delayed. I can click on messages in my inbox but they won't display for a while. Instead I see the message "No Message Selected" in the preview pane.

The other problem I have is to get Mail to respond when switching to the app after working in a different app. This does not always happen but frequently enough to stop a productive workflow.

I am using a MacBook Pro with 4 GB RAM and I have 25% free space on my HDD. I have rebuilt the index for my mailboxes but that did not help either. Does anyone have an idea how to solve this problem?

Since you're having problems after a ML update, why not take your question over to the Mountain Lion forum?

You may find other users there experiencing the same problems and there may be some solutions...

Clinton

This post from another thread solved my problem:

https://discussions.apple.com/thread/4139074?answerId=19044030022#19044030022

I was also experiencing lags when switching mailboxes or even when clicking through my mails in the inbox or quitting the app. Not as severe as others described it, but still 0,5 to 1 second - in two words: "not adequate" for an up-to-date MBP. Could be relevant that I deleted both files of the name mentioned ("com.apple.mail.plist"), one in the /Library/Preferences in the root level and one in /Library/Preferences in my user folder.

Other than that I did not experience any other issues with the ML update.

Werner

I just deleted com.apple.mail.list and restarted mail. Seems to work perfect now. Whereas it was using more than 600 MB (activity monitor) before, it now is only using some 32 MB.

I also have the problem with very slow sending of messages in Mail. It gives me the spinning beachball for hours. It started recently for me and I'm still on Lion, 10.7.4 for now. So, it might not be related to upgrading to Mountain Lion, 10.8.

Where is com.apple.mail.plist ?

I don't have it in Preferences or Application Support

Hi,

This solution worked for me:

http://www.fixkb.com/2013/03/apple-mail-application-very-slow-to-respond.html

Don't forget to restart the mac after using the fix.

My mail is working seamlessly again.

I called Apple support and they had me run the update for Airport and everything runs great

Mail had been taking 98% of cpu now .07

Thanks for this link - a simple, obscure, but very effective fix that I'm amazed I even have to worry about. Getting ever closer to Windows dysfunction.