Error in downloading mail on IMAP after ios 18 upgrade

There are 2 error i have notice in my dovecot setup while my iPhone Mail app given POSIX 96 error.

First time dovecot given the error "imap-postlogin: Error: ERROR 145 (HY000) at line 1: Table './last_login/lastauth' is marked as crashed and should be repaired", that is have fixed by repairing that table in mysql.

Second time dovecot given the error "imap(......@..........in): Error: mmap() failed with file /var/vmail/vmail1/..../Maildir/dovecot.index.cache: Cannot allocate memory". For this error i have increased default_vsz_limit from 256M to 512M.

Overall My Understanding is Dovecot having any error in it plugin apart from IMAP protocol, other clients are ignoring it, where us the latest Mail app throwing the error in client side. So blaming iOS18 or new Mail app is not good.

May be i can help you to fix if you share the truncated logs while accessing Mail app to your server.

Same Problem for me - Support said the problem is known and seems to occur if you use your own domains

“Same Problem for me - Support said the problem is known and seems to occur if you use your own domains”

Did they suggest a workaround pending a fix? This is a serious problem.

I'm getting the message Network error POSIX 60 when trying to get my icloud mail. My phone also does not work on the wifi since the update? Any help would be greatly appreciated.

same problem with e-mail after installing IOS18.

Same here!

If you had of mentioned it was a Outlook account the two suggestions I make, is 1. You reenter it using the Exchange option and if that doesn't work, then I usually suggest you download the Outlook app on the App Store.

After I installed OIS18 on iPhone I’ve had this problem with getting BT mail with the POSIX 96 network error message. However after deleting and reinstalling my email account, it’s working again. However the same email client had no issue whatsoever with my G Mail account !

As per my understanding POSIX 96 error is related to your server side error. Also based on your issue explanation, your mail server might be having session handling/holding issues. Check your IMAP/POP3 server error log or run your IMAP/POP3 server in debug mode to get more information.

Same issue, on iPhone and iPad, started with upgrade to iOS 18, not fixed with 18.0.1.

I can access the same accounts fine from a desktop MacOS Mail app.

Dovecot (v2.3.20) debug logs show a successful TLS connection and authentication, opening the INBOX, executing LIST, then immediately disconnecting. No errors reported on the server side.

I also run a slightly older version of Dovecot (v2.3.17) on another server and my iOS devices can get mail just fine. I'm wondering if the iOS 18 clients are doing something slightly non-standard causing newer Dovecot versions to close the connection.

Hi all,

I have the same problem (Network error POSIX 96). The emails do not download and refresh correctly through the native Mail app. Sometimes, they do download but I am unable to open the content of the email. I have contacted the local provider of my email and I have been informed that the issue is on Apple side. When will this be fixed? This is a serious issue. :(

I get POSIX 61 on BTinternet. This is a huge issue, we carry our phones with us and they are also authentication devices be it via MFA, text or MAIL - this is a big problem since updating to iOS 18.0.1 which I installed yesterday and have since had this issue.

Apple - is there a fix coming soon please?

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.

mangalapandi wrote:

I have plan to reproduce this error in my server maintenance time. if i am able to reproduce it, i will update about the specific protocol error that may help apple/others to fix the issue.

But you indicated earlier that you fixed it on your dovecot server. What did you do?

mangalapandi wrote:

There are 2 error i have notice in my dovecot setup while my iPhone Mail app given POSIX 96 error...

I will have a look at my logs as soon as I have a chance. Thanks very much for your useful information and offer to help.