High Mail CPU with El Capitan

Removed Avast, issue is gone. Thanks !!

I tried everything people have been suggesting in these forums but I didn't get anywhere until I decided to deal with the 22k+ unread emails that have been amassing over the last few years. I simply marked these all as read and now mail is working much better. It still lags behind Mail in iOS, but it's no longer necessary to restart Mail for OSX each time I want to download emails. Previously, emails which were already appearing on my phone did not appear on the desktop, despite clicking "Get Mail" . A Mail.app restart was required and even then it would take several minutes rather than seconds to download the them.

So nice to have just 12 unread emails in that inbox!

I now also have the problem that I sometimes have to click on a mail 3 or 4 times before the little blue "unread" dot disappears and it's marked as read. Anyone else have that?

I think that Mail.app should be able to cope with thousands of emails in an IMAP inbox at at time. We live in a Gmail-style world where people don't always file stuff away neatly - I guess people think "why should I waste time setting up a folder structure when you I can just search in Spotlight (or in the Gmail interface on the web)?". Personally I archive mine in my multiple Google Apps accounts every few months only, and I get many thousands of mails in that time.

Interesting that other threads are discussing the problems with Mac mail.

Re: El Capitan running slowly?

Apparently deleting the mail logfiles works well.

El Capitan running slowly?

I personally think it's more to do with the developers having terabit networks yet us in the real world suffering from average performance. Still, there's a new beachball to look at...

Hello everybody !

Well, Well !

I was too fast in my previous conclusion :-( :-( :-(

After some more hours, my MacBook became again a frying pan!

In fact, to recover a normal MacBook the solution has been to deactivate completely the Avast mail shield.

There is 10 days now that I am using the MacBook with this configuration and everything is "as it should be".

Hoping it could help.

Regards,

Jean-Claude

Hello,

I have the same problem since I upgraded to El Capitan. My MacBook Pro 15" (Late 2011) with 16 GB RAM and 2,2 GHz i7 goes crazy after a couple of minutes after I started to work. I don't use any CPU-intensive apps, only a standard office stuff (Safari, Mail, Excel). I found a lot of system tasks consuming a lot of CPU - backupd, mds/mds_stores/mdworker, syncdefaultsd, accountsd, kernel_task and especially Mail. I have exchanged battery, reinstalled OS X from the scratch, I don't use any antivirus software but I can still boil eggs on my MBP as is it hot as ****. ;-(((

I sent a lot of sysgiagnose reports to Apple, but unfortunately non of it helped - there is still no conclusion nor solution for this culprit. And it's really annoying. It seems like something is heating CPU permanently, so when you run any quite intensive task (like checking the mail), your MBP goes crazy, fans spin for 100% because of the heat.

Even when I write this entry, my computer "does something" for 25% of its CPU (kernel_task 21,5%).

I hope anybody will find any reasonable solution, because it's really annoying.

Pavel

P.S. Do you experience this issue when running on battery? I found it mainly when I'm connected to the AC plug.

I'm having the same issue... re-installed El Capitan from scratch (I was running the Beta version) but Mail does the same thing. Runs over 100% CPU and constantly downloads emails (no idea which ones). It's also extremely slow to move emails and create new mailboxes. I guess it's back to Outlook! Hopefully Apple will update the app soon....

> P.S. Do you experience this issue when running on battery? I found it mainly when I'm connected to the AC plug.

Just a small point; when the laptop is charging it will naturally heat up a bit more - due to the power through the charging circuits. I find that the fan comes on more whilst the charging light is orange than when it's green, and especially when it's doing a 'deep' charge.

I was suffering quite heavy problems with Mail, too. Actually i had about 3000 folders and 65.000 mails getting synchronised with IMAP. CPU usage was steadily over 150% up to 220% and i realized it was due to synchronisation. After i read some articles here, e.g. this one, i changed the Protocol to Exchange, which would be possible, too, as the mail accounts on the server are run by Kerio. After synchronising all of my mails with Exchange, now and CPU problems are gone... seems there is a big problem for Mail on El Capitan with huge mail accounts, which was never a problem on Yosemite and other OS Xs...

I was suffering quite heavy problems with Mail, too. Actually i had about 3000 folders and 65.000 mails getting synchronised with IMAP. CPU usage was steadily over 150% up to 220% and i realized it was due to synchronisation. After i read some articles here, e.g. this one, i changed the protocol for my biggest account to Exchange, which would be possible, too, as the mail accounts on the server are run by Kerio. After synchronising all of my mails with Exchange, now, all CPU problems are gone... seems there is a big problem for Mail on El Capitan with huge mail accounts as IMAP protocal was NEVER a problem on Yosemite and other OS Xs...

Agreed. I did the same and experienced significant improvement in overall CPU usage. My IMAP account was not that large, so I think it is some incompatibility with certain IMAP servers more than the size of the account.

I tried to disable Spotlight indexing and re-enabled it again and I think it helped a bit. Try these (I took this from http://osxdaily.com/2011/12/10/disable-or-enable-spotlight-in-mac-os-x-lion/):

1. execute this command in Terminal:

sudo launchctl unload -w /System/Library/LaunchDaemons/com.apple.metadata.mds.plist

2. wait until it stops all tasks (I waited for one hour - just to be sure, but I think it's not needed to wait so long)

3. execute this command in Terminal:

sudo launchctl load -w /System/Library/LaunchDaemons/com.apple.metadata.mds.plist

After this, you should see Spotlight processes (mds, mds_stores, mdworker) to spike a little, but then the whole MacBook is calmer and not going crazy so much as before.

4. just to be sure everything is ok - restart the notebook.

Although I don't know, what has changed, it seems it helped me.

two comments:

1. Spotlight indexing should only be temporary - it gets very high for minutes to hours after a major upgrade or even new disk addition. Then its insignificant.

(if this is really your issue let it run overnight and it will be gone)

2. This is far afield from the original issue - by broadening to UN-related issues the thread becomes far less useful

G

quote:

i changed the protocol for my biggest account to Exchange, which would be possible, too, as the mail accounts on the server are run by Kerio. After synchronising all of my mails with Exchange, now, all CPU problems are gone..

This makes perfect sense. Question: does your mail provider not specify to set up as exchange? Exchange is *not* (quite) IMAP and should not be set up as IMAP.

What do their configuration instructions say?

Grant

Hi Grant,

actually it is a Kerio Server and the Kerio Connect Assistant (the configuration instruction) automatically sets up all mail accounts as IMAP itself... Additionally the provider mentioned some time ago, that it would be possibel to set up the account manually as an Exchange account, too. So i tried it and get the high CPU usage only while synchronising all accounts for a very short and limited time. Which seems o.k. as after the short synchronisation Mail reduces energy consumption and CPU usage to a very low level again (about 3% of CPU).

While working with IMAP Mail kept this huge CPU usage for a long time and additionally each time the program window of Mail got to the front... that's all i know.

Best