Error in downloading mail on IMAP after ios 18 upgrade

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.

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.

mangalapandi wrote:

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

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

I saw nothing interesting in IMAP logs on dovecot server. I see the login with no error, and no errors following.

Not set to debug, but I think it will be less effort to wait until Apple fixes iOS mail.

Thanks for the offer of help.

hi - just talked to Naisha in apple support. after much troubleshooting she had me delete the VPN App i had on my phone and mail started working normally.

try that if you have a VPN app on your phone.

Seems to be an issue with the Mail app using IMAP in general. Happens with gmail giving a Network error (POSIX 54). Waiting for the update to hopefully fix this as email is not usable on the iPhone Mail app.

Thanks!

That's very discouraging news. Last month I had to roll back my iPhone to 17.6.1 after ios18 was automatically installed. I've been eager to try the first round of Apple Intelligence but I'm not willing to forego the ability to access my email.

Thanks, much appreciated! I hope you will be posting here in this same thread so I’ll get a notification. i’m totally ready to move back to Mail app after a few months in Outlook where I get work email notifications in the same app…

I’ve been having the same problem. And it’s been going on for probably two years on and off. My email works just fine on my computer and my iPad but not my phone. I have a Comcast email account and sometimes I get a massive dump of emails and then other times it just says incorrect password and I can’t get anything for days. And then all of a sudden it will work for two weeks or six months and then it will happen again. Nobody can seem to fix the problem.

It's fixed! It magically started working again on both my iPhone and iPad yesterday. They must have fixed something on the back end, because I didn't do an iOS update this week and didn't change any settings.