Mail.app displaying email addresses with numbers

[miles8888]

Running Sonoma 14.1.1 on MBP - Using Mail.app with Gmail IMAP.

In Mail.app, when viewing an email, the To: email addresses are showing up with a string of numbers.

For example instead of:
me@gmail.com
I see:
<1502D7E4-E347-40C2-911A-FDB643323449DCAF@gmail.com>

This only appears when viewing emails. When I compose an email and enter an email address, it fills in normally./
I do NOT see this behaviors when using Gmail in a browser.
I've reviewed my settings in Mail.app and Gmail, but do not see anything that could be causing this.

Grateful for any suggestions.

 

[miles8888]

Bump….

 

[miles8888]

Grateful if someone has any ideas about this. Thank you...

 

[gilby101]

The 1502D... is likely the name of the folder in ~/Library/Mail/V10 for that gmail account. Just a possible explanation as to where the numbers have come from. Not a solution in any way.

 

[gank41]

See my post below, not the exact same issue, but it seems to have fixed a number of things for me and a couple others...

Mail Import Failed After Sonoma Upgrade

Hi everybody, After installing Sonoma on my 2018 Intel Mac mini, Apple's Mail App all of a sudden decided it wanted to "Import my Mail" in order to continue.. Ok, sure. That happens from time to time with different app databases needing to be updated and whatnot. Well, in my case, maybe yours, I...

forums.macrumors.com

 

[chabig]

Try running Mailbox > Rebuilt. There is no risk and it might work.