Mac OS Sierra Mail.app doesn't save settings

[pinkoos]

Hi,

Another issue with my wife's Macbook Air (Sierra, all software updated).

In her Mail.app, we've noticed that for her configured fastmail account, under the "Mailbox Behaviors" settings, if we change the "keep deleted mail" option to "forever" the setting doesn't stick. We also don't get asked if we want to save these settings when closing out of the dialog. I don't know if that's a new thing in Sierra, but it doesn't ask to save. So, when she closes out of the dialog and then goes back into it, the setting has reverted to "one month" (instead of "forever").

She's basically lost all her trash prior to the last month b/c this has happened.

I can't seem to find any instances online of people having similar issues (maybe I didn't phrase my search terms correctly) and, so, don't have any suggestions to try and fix the problem.

Any thoughts or ideas?

Thanks.

[modelamac]

Does the same thing happen to other Users on that Mac?

Have you tried rebuilding the mailbox?

Have you Repaired the Disk via Disk Utility?

[pinkoos]

Will try your suggestions this evening when I'm back home.

Thank you.