Fix High CPU Usage While Using Mail on macOS Catalina

Are you experiencing a spike in CPU usage in Mail after upgrading Mac to Catalina? Do not worry, you are not alone, there are many Catalina users who are facing high CPU usage when Mail App is open on macOS Catalina. Today in this article I am going to provide a few workarounds to fix high CPU usage for Mail on Catalina. This has worked for many users, hope it works for you. Let us start with a practical scenario.

High CPU Usage in Mail Catalina

I have mail open and my CPU usage is between 111- 300% int he activity monitor. It is extremely slow, and bogs down the rest of my machine. The fan is on constantly. I have attempted to Force Quit, Re-index, Remove Accounts, etc. Anybody else seeing this?

Source: Apple Community

Like the above Catalina user, there are many others who have noticed a great spike in CPU usage in Mail. Please follow the workarounds provided below to lower down the CPU usage.

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Force Quit “accountsd” Process

Many users were able to reduce the CPU to a great extent after force kill of “accountsd” process. Follow the steps provided below to force quit “accountsd” process.

  • Close Mail.
  • Press Command + Spacebar to open Spotlight.
  • Type Activity Monitor in Spotlight search.
  • Click on Activity Monitor when it pops up.
  • You can also open Activity Monitor from the Utilities folder of your Applications folder.
  • In the Activity Monitor app, under the Process Name list find “accountsd” process.
  • Now click on the Force Quit button located in the upper-left corner of the Activity Monitor app.
  • Relaunch Mail.

Force Quit accountsd Process

Fix Corrupt Addressbook

It has been noticed that a corrupt address book seems to be the reason for high CPU usage for the Mail app. To fix it, perform the steps provided below:

1) Backup your contacts and then close the Address Book, to do so, from the Contacts app on your Mac, click on File located on the top of the screen. Select Export > Contacts Archive, select a location, then click on Save.

2) To make sure that you have all of your contacts visit

3) Open Activity Monitor and check AddressBookSourceSync is running or not. In case it is running, make a double click on it and choose Quit.

AddressBookSourceSync activity monitor

4) Open User’s Library. To do so, click on an empty space on your desktop to activate Finder. Press and hold the option key and click on the Go menu in the Finder menu bar.

Open User's library on mac

5) Expand Application Support and then expand Address Book. Here delete everything inside the Address Book folder except plist.

Address Book under application support

You can find AddressBook in the Application Support folder.

6) Go to System Preferences and open iCloud.

iCloud in system preferences

7) Now go to Contacts and uncheck the box and then recheck the box to start the sync.

Check contacts in iCloud

Additional Workarounds to Fix High CPU Usage in Mail on Catalina

  • Disabling and re-enabling my Gmail account resolved the issue for many users. If you have multiple email accounts utilizing multiple email services then that can be the reason for CPU usage spike- many Catalina users were able to lower down the CPU usage by simply disabling the Gmail account in the Apple Mail app. If you have any non-working Gmail account or any Gmail account that does not matter to you then you can try disabling it. Go to Mail > Preferences > Accounts > uncheck Enable this account under Account Information for your Gmail account.
  • Turning off the FileVault helped few users reduce the CPU usage for them. Go to the Apple menu > System Preferences, then click on Security & Privacy. Go to the FileVault tab and turn it Off. Please Note: When you turn off the FileVault, the encryption is turned off and the contents on your Mac are decrypted.
  • Few Catalina users turn off the iCloud feature and were successful in minimizing the CPU usage spike in Mail. Go to the Apple menu > System Preferences, then click on Apple ID, then deselect Mail. Important Note– When you turn off an iCloud feature on a device, information stored only in iCloud for that feature is no longer available on the device.

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I hope this article helped you to Fix High CPU Usage While Using Mail on macOS Catalina. In case, the issue still persists then please contact Apple Support for further assistance.

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