Mail extension missing from the share menu

Hi there RMW.KCW,

We appreciate you getting back to us.

Since the checkmark is missing, the default email reader may not be set to the macOS Mail app. To check which mail app you have selected as the default, open the built-in Mail app on your Mac, click Mail (in the menu bar at the top left) > Preferences, then click General. Next, choose the built-in Mail app from the ”Default email reader” menu.

From there, it may ask you to sign into your email account or add a new account.

You can find more information here: Change the default web browser or email app on your Mac

Thanks again for your post!

Take care!

Hi there RMW.KCW,

Yes, that may be the case on this one. If the file is larger than your email account allows, and you're not using iCloud as your main email address, you may need to find an alternate way to share the slideshow or Memories.

If you use iCloud for photos, even if you don't use the mail account, you can create a link to share with others. Check out those steps here: Share photos and videos on iCloud.com - Apple Support

Have a great day!

Cheers!

Hi there RMW.KCW,

Welcome to the Apple Support Communities!

You've stated you're having an issue with adding a checkmark next to Mail in System Preferences > Extensions > Share Menu on your iMac.

Some content, depending on apps being used and type of item, can only be shared with certain extensions, but if you're also missing the checkmark next to Mail, do you have an email account set up in the Mail app on your Mac?

Check out this article for more information on when certain options will be able to be used from the Share menu: Use the Share menu on Mac - Apple Support

Have a nice day!

Take care!