Mail.app Ridiculously High 100 percent CPU and Memory Usage

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Level 1

41 points

Mail.app Ridiculously High 100 percent CPU and Memory Usage

Mail.app (v. 8.2 on 10.10.4) regularly uses 100 percent of my cpu and memory. This is on a beefy Mac Pro with 64 GB RAM ⚠:

Mail.app is essentially unusable because of this. It takes 30 minutes to encrypt and send a simple SMIME email. Large (a few MB) attachments exacerbate the problem. The mail account is on an Exchange server. I have hundreds of SMIME certificates in my keychain. This is a lot, but not too much, and is really a typical enterprise environment at which Mail.app is failing.

Any suggestions to fix this?

I'd switch to a different enterprise mail client if I knew of a better option. Any help either fixing Mail.app or a recommendation for a capable enterprise mail client on OS X would be greatly appreciated.

Posted on Aug 3, 2015 3:03 PM

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Answer 1

KiltedTim

Level 10

195,537 points

Aug 3, 2015 3:15 PM in response to essandess

How big is your mailbox? That's way out of line...

As for an enterprise mail client, have you considered Outlook, since you're using Exchange?

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Answer 2

Kappy

Level 10

361,741 points

Aug 3, 2015 3:18 PM in response to essandess

Quit Mail ASAP. Runaway applications can shorten battery runtime, affect performance, and increase heat and fan act… Be sure to clear this up before using Mail. See the following for possible help: Isolating an issue by using another user account, Isolating issues in Mac OS X, and Mac OS X- How to troubleshoot a software issue. Also, Visit The XLab FAQs and read the FAQ on resolving various OS X problems.

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Answer 3

Kappy

Level 10

361,741 points

Aug 3, 2015 3:20 PM in response to essandess

Perhaps the best enterprise mail client would be Outlook which is part of Office 2011.

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Answer 4

KiltedTim

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195,537 points

Aug 3, 2015 3:21 PM in response to Kappy

Kappy wrote:

Perhaps the best enterprise mail client would be Outlook which is part of Office 2011.

And office 2016... The 2016 client is much nicer to work with than 2011.

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Answer 5

essandess Author

Level 1

41 points

Aug 3, 2015 3:30 PM in response to KiltedTim

My Inbox has around four thousand messages. That shouldn't be an issue.

Small messages (I just sent one) take around 60 seconds to sign and encrypt on a Mac Pro! Large (a few MB) signed+encrypted messages just cause Mail.app to fail.

I'll admit that I have strong negative opinions about Outlook, though I've had to use it as a last resort before. There has to be a better option than Outlookl

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Answer 6

essandess Author

Level 1

41 points

Aug 3, 2015 3:43 PM in response to Kappy

I'm confident that trying another account won't isolate this problem, which appears to be a failure of Mail.app to scale with an enterprise PKI or play nicely with Exchange servers.

I have tested this across four different platforms:

2013 Mac Pro with 64 GB RAM
2011 MacBook Pro with 16 GB RAM
2009 MBP with 8 GB RAM
2007 MBP with 6 GB RAM

The problem is identical across different platforms and accounts. The common thread is Yosemite's Mail.app with PKI and an Exchange server. I've used openssl to sign+encrypt/decrypt some of my raw emails by hand and the load isn't close to Mail.app's by orders of magnitude.

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Answer 7

Linc Davis

Level 10

209,547 points

Aug 3, 2015 3:54 PM in response to essandess

1. If you've installed any third-party plugins for Mail, such as "SpamSieve," remove them according to the developer's instructions, then log out or restart the computer and test. Back up all data before making any changes.

2. In the Advanced settings for the mail account, uncheck the box marked

Send large attachments with Mail Drop

if it's checked. If you have more than one account, repeat with each one. Relaunch Mail and test.

3. I've seen a report that Mail may leak memory if a Gmail or Google Apps account does not have the "Auto-Expunge" option enabled in its settings on the website. I can't confirm.

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Answer 8

essandess Author

Level 1

41 points

Aug 3, 2015 5:11 PM in response to Linc Davis

Thanks Linc, but none of those three options apply: no plugins, no Mail Drop, no google.

I'm guessing this is an unresolved PKI bug in Mail.app.

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Answer 9

Linc Davis

Level 10

209,547 points

Aug 3, 2015 5:18 PM in response to essandess

Does that mean you've installed an S/MIME certificate?

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Answer 10

Kappy

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361,741 points

Aug 3, 2015 5:22 PM in response to KiltedTim

Office 16 is beta software.

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Answer 11

Kappy

Level 10

361,741 points

Aug 3, 2015 5:29 PM in response to KiltedTim

Office 2016 is clunky and buggy. Not ready for prime time. it also requires an annual subscription to Office 365. I'd switch to Thunderbird before switching to Office 2016. Not my cup of tea. But then I hardly have much need of it since retiring. I use Excel, mostly, and sometimes Word when opening older Word documents i still have. Too bad that Libre Office and its cousins do not possess good, full implementations of Excel. 🙂

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Answer 12

essandess Author

Level 1

41 points

Aug 3, 2015 5:44 PM in response to Linc Davis

Linc Davis wrote:

Does that mean you've installed an S/MIME certificate?

Yes—one for signing and one for encryption, issued by an enterprise PKI. The root CA is installed and trusted for X.509 Basic Policy, and the certs's RFC 822 Name matches my email (case sensitive correct).

PKI is correctly configured and works,* but has this crazy cpu and memory suck behavior, especially for email size exceeding a MB or so.

*One caveat, not sure if it's relevant, or a separate Mail.app bug: Mail.app DOES NOT show the encrypted lock or signed logo for properly signed and encrypted emails in my Inbox. I've confirmed via command line OpenSSL and Mail>View>Message>Raw that the emails are signed and encrypted correctly.

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Answer 13

essandess Author

Level 1

41 points

Aug 3, 2015 5:35 PM in response to Kappy

May we please all agree that MS products are plain awful and not derail the thread?

LIke it or not, Outlook is a functional enterprise option in the face of Mail.app bugs.

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Answer 14

KiltedTim

Level 10

195,537 points

Aug 3, 2015 5:37 PM in response to Kappy

Kappy wrote:

Office 16 is beta software.

No. It's not. Office 16 went gold on July 9th, but only for subscribers to Office 365. The standalone version will not be available until September, when Office 2016 for Windows is released. So far, it's been very stable for me. I'm not a fan of Thunderbird, or anything from the Mozilla camp, and last time I checked, Thunderbird requires 3rd party add ons to work with Exchange without resorting to POP3 or IMAP, neither of which are permitted for connections to our corporate mail system for security reasons.

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Answer 15

Linc Davis

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209,547 points

Aug 3, 2015 5:42 PM in response to essandess

I have seen reports of this behavior but I can't reproduce it myself. Perhaps some certificates trigger it and others don't. I have a certificate from StartSSL that causes no problem.

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