mangalapandi wrote:
This may not be the Mail App issue, When i got new iPhone with iOS18, i got the same issue after the migration and even i deleted the account and recreated in Mail app, it did not worked. Then i have checked my server about the dovecot error log and i noticed that its had issue in keeping the authentication session and i fixed it, then Mail app started getting message and its not showed any error related to POSIX 96 till now.
This is very significant, and probably the most useful post I have seen respecting this problem! But, how did you fix it?!?
This means, ironically, apples own (discontinued) server software also won't work with iOS 18 because it runs dovecot.