Clear all

"Out of Application Memory" -- indexing 3.8M emails!


Topic starter

Hi all,

I've got a doozy of a situation where a client had us swap out his SSD on a 2015 MBP. We installed a fresh copy of High Sierra, set up a test user, then did migration assistant. He wrote us saying that he was getting messages that he was out of application memory, with only the Finder running. When we went back to take a look at what was going on, he revealed that he had 3.8 MILLION emails in Mail. In looking at Activity monitor, mdworker is the process that seems to be going nuts, which appears to be related to Spotlight. Apparently the migration forced his machine to rebuild the mail index and try to sync all of that down from G Suite? I have no idea how to deal with this. We tried putting the Users > Library > Mail folder in the Privacy section of Spotlight Preferences, but it doesn't seem to resolve.

I suggested a few things might work, including:

  • leave on overnight with system sleep off to see if it stabilizes
  • safe boot and see if it behaves better without any 3rd party apps running
  • using onyx to delete the local mail envelope and start from scratch
  • total nuke and pave and start his OS from scratch
  • forgetting Mail and dealing with that mess in the browser only

But these are only guesses. I don't want to waste too much of our time or his. Has anyone dealt with anything of this magnitude? 


2 Answers
Topic starter

Finally figured out the issue. Deleting the mail index with Onyx didn't solve it, but simply removing and re-adding the gmail account got everything in order. Turns out he had FAR less than the ludicrous amount of emails we were seeing in the initial import. Not sure where that number came from, but clearly there was some corruption in the mail index. 🙂


I think your last option of working solely via browser interface is going to be the least hassle due to the size of the database you're working with. I have a colleague who swears by moving his customers away from app based mail clients coz it saves him so much grief from when local databases (of whatever OS variety) get corrupted.

The downside of that is that the customer no longer has a local backup copy and will be reliant on Google's backup/restore procedures.... unless you implement a cloud based G-suite backup (or possibly something like Synology G-suite backup).


Thanks for the advice. To add another element to this, it looks like the issue is not necessarily sluggishness, but rather that the Mail import crashes and fails, rendering Mail useless.