Apple Mail 16.0 keeps duplicating attachments when I write an email

How are you adding the attachment to the email?

Give this a try: boot into Safe Mode according to How to use safe mode on your Mac and test to see if the problem persists. Reboot normally and test again.

NOTE 1: Safe Mode boot can take up to 3 - 5 minutes as it's doing the following; 

• Verifies your startup disk and attempts to repair directory issues, if needed

• Loads only required kernel extensions (prevents 3rd party kernel/extensions from loading)

• Prevents Startup Items and Login Items from opening automatically

• Disables user-installed fonts 

• Deletes font caches, kernel cache, and other system cache files

NOTE 2: if you have a wireless keyboard with rechargeable batteries connect it with its charging cable before booting into Safe Mode. This makes it act as a wired keyboard as will insure a successful boot into Safe Mode.

Sean Butler2 wrote:

When I write an email Apple Mail 16.0 adds multiple versions of attachments to the draft. Any solutions please.

What happens if you compress the item before attaching...(?)

Control click—>Compress

Add attachments to emails in Mail on Mac

Hello, Did you ever receive any guidance on how to correct this (inconsistent) issue? I have this happen periodically and it is very frustrating and 'unprofessional'—and then it takes time to have to resend the email and—fingers crossed—hope that it doesn't do it again.

Thanks!