I am unable to download my mail using the native mail app after upgrading to IOS 18. I am getting the following error; “Network Error (POSIX 96)”
The mail configuration is on imap with SSL.
iPad Pro, iPadOS 18
@ferrerod:
Here's the main part of the response I got from Fastmail who diagnosed and solved the problem on my account. It seems there was a bug in their mail engine that was benign until the iOS18 update, then no more. I hope this helps.
We had a bug which put random data into the HIGHESTMODSEQ value for some users. Their account was affected by this. We didn't think it was an issue because there was still heaps of number-space left, but the HIGHESTMODSEQ values were higher than a signed int64 can hold. This was fine because we use an unsigned int64_t internally, but the spec was updated a few years ago to make it a signed value, so we were strictly wrong.
Apple's parser couldn't handle these oversize numbers, and failed.
--
This has now been fixed by resetting the HIGHESTMODSEQ value for these users which also means this will never happen for them again.
ferrerod wrote:
Did fastmail tell you what technically they did? No one else has a workable solution. Some of us support our own mail serves - though perhaps rare.... would be great if you could get them to tell you exactly what they did for IMAP solution.
I have 3 IMAP (older dovecot) accounts and 2 of the 3 work fine with iOS 18. The only difference is the number of messages and folders. The two that work have about 1000 or less messages and the 'standard' set of mailboxes. The one that doesn't work has 12,000+ messages in the inbox and a 100-200 folders for organizing. All 3 accounts contain 'special characters'...
I just tried deleting the Mail app itself and reinstalling it. For several hours it showed promise of a fix, but alas, I deleted some emails on macOS Mail app on that account and a few new emails rolled in and that iOS 18 Mail app has now stopped syncing correctly. Maybe I need to start looking at alternatives to Mail for now...clearly Apple has dropped the ball with iOS 18 and doesn't show due diligence to dig deeper for a fix.
It might be useful for affected users to identify their email provider when describing their problems. As I pointed out below, my problems were due to a bug with my email provider's setup they were able to patch. Are there particular email servers vulnerable to this problem?
Can you please give us the exact imap_capability value? I am running dovecot 2.2.27 on linux with many combinations of values for this string, but the iOS 18.2 on iPhone gives "bad certificate format -9, 808. It also appears the phone is not passing on the user even though it is configured to do so.
This only happens on iOS 18.2 for me.
honestly sounds like you have some sort of other issue. if you look a couple replies back someone stated that using telnet to connect to your imap server should report your current capability string. you could omit the IDLE portion and use that in your config file. but please be aware that the community here gives no warranty on your mail 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.
My guess is Apple is investigating each case individually before they declare it as a bug. It would help if more people raise cases with Apple support. Frustrating, but then it is what it is.
Unfortunately nothing to report. They keep calling me off and on but looks like the engineering team is not prepared to accept it as a bug. Might help if more people raise cases with Apple.
https://doc.dovecot.org/2.3/configuration_manual/namespace/
In my case (Debian), it's in /etc/dovecot/conf.d/10-mail.conf, look for 'namespace inbox'
Well on the mac you can rebuild the Spotlight index if you want but it won't help the other devices. I suggest that you turn them off and then back on again.
I agree with nxnw. The only way to get Apple to accept the problem and do something about it is if more people raise support cases.
ios 18 problems infecting email - IMAP failures on multiple accounts... iCloud, Google, Outlook... Apple is losing my loyalty
Hi All,
I'm experiencing the same problem. No personal IMAP or POP3 accounts work, even though the SSL and TLS certificates are fine.
This is a very big problem. If Apple doesn't fix it quickly, I might go back to iOS 17 or switch to another brand.
I believe that for Apple and its development team, it should be quite simple to fix an issue like this, and I find it very concerning that a solution hasn't been provided yet. After all, what complex code could be behind a function you've been implementing for over 10 years? I strongly urge you to resolve this quickly, or many of us will be forced to leave a platform that has so far been both reliable and secure.
Thank you.
That is an interesting hint. What exactly did you do? Customization in dovecot.conf? And if so, what exactly?
I may be able to solve the problem for myself too. I found dovecot.conf in my mail configuration...
Thank you for any further information !)
Error in downloading mail on IMAP after ios 18 upgrade
