How To Fix Mac Mail App
Is it possible to uninstall and reinstall the Mail app without reinstalling the entire OS?
Sorry, but no.
Mac Mail App Update
Updating your software may fix the problem you're having. Click the Apple menu and select 'Software Update'. Download and install any available updates. This tool will find and install updates for your operating system and any apps installed through the Mac App Store. Update non-App Store apps individually. On October 21st Apple released the El Capitan 10.11.1 update which claimed to have fixed Apple Mail problems with outgoing server issues and message display problems. We recommend before proceeding that you install this update first to see if it fixes Mail which you can install by going to the Mac App Store and selecting “Updates” at the top.
Once in a while, your Mail.app (sometimes referred to as 'Apple Mail' or 'Mac Mail'), stops receiving new mail. You may be able to verify that you are getting new mail via webmail, another email client or computer, or even via a mobile phone. When this happens, the fix is extraordinarily easy! In this article, I’m using Apple Mail on macOS 10.13 and the native Mail app on iOS 11 to illustrate the most common problems and their solutions. But if you’re using Microsoft Outlook or another email client, note that most of the steps below still apply.
How to Fix a Hung or Crashed Mail.app Screenshot: OS X Lion Mail Import Screenshot: OS X Lion Mail Import. I’ve found that deleting Mail.app’s “envelope” index seems to alleviate crashing or hanging. I suspect what happens is, a malformed email message is received, and Mail.app hangs on processing that.
Have you tried either rebuilding the particular email account that is having the issue or rebuilding the entire message database?
To rebuild a single or multiple Apple Mail mailboxes:
- Open the Mail app, and then, select one or more mailboxes.
- From the Mail app's menu bar, select Mailbox > Rebuild
How To Fix Mail Application
To rebuild the Mail app message database:

How To Fix Mac Mail App Store
- Quit Mail (if running)
- In Finder, navigate to:
~/Library/Mail/V3/MailData
- Drag the following three files to the Trash:
- Envelope Index
- Envelope Index-shm
- Envelope index-wal
- Relaunch the Mail app.