Which plist contains IMAP details host:p52-imap.mail.me.com -- port:0

Which Mac OS Ventura plist/file contains details for IMAP email connections? One of my iCloud accounts is giving me the following in Connection Doctor:

INITIATING CONNECTION Jan 04 21:13:01.610 host:p52-imap.mail.me.com -- port:0 -- socket:0x0 -- thread:0x6000105fca00

Obviously the connection (for incoming mail) fails. (Needs to be port 993 not 0.) SMTP connection (for outgoing mail) works fine. Same account also works fine in both directions on iPhone and iPad. So it appears that I have a corrupted preference file somewhere in Mac OS. Deleting and re-adding the iCloud account doesn't work either. (Unfortunately Mac OS no longer allows you to specify IMAP port numbers for iCloud email accounts.)

Thanks in advance.