Mail duplication

### What Happened?

Mails are shown twice (sometimes even three times) below each other:
I have two accounts configured and selected the combined view which shows mails from all accounts in one place. The duplication happens only if I launch the app with this view selected. If I select a specific account's incoming mails and then go back to the combined view, the issue disappears.

### Steps to Reproduce

1. set up multiple mail accounts
2. select he combined incoming messages view in Mail
3. close/open the app a few times - mails will appear twice in the view

### Expected Behavior

Every mail should appear only once

### OS Version

7.x (Horus)

### Software Version

Latest release (I have run all updates)

### Log Output

_No response_

### Hardware Info

_No response_