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.
ferrerod’s experience (his small inboxes work, his big inbox does not)tends to support a theory I have about this problem. The theory is that it is some characteristic of some individual emails that iOS 18 mail chokes on. When it hits the emails that it has a problem with, it’s done.
I had tens of thousands of emails in my inbox. When I first tried deleting and reconfiguring the account (one of the suggestions that has helped some people here) it choked almost right away. After I deleted a bunch and moved another bunch into local folders, I tried again (deleting and reconfiguring the account). This time, it worked better. This was demonstrated by the fact that a much higher number of unread emails was shown on the badge. Still, it eventually choked again.
One idea I had was that the presence of non-ascii 128 characters in the subject line of a email was the problem Mail was encountering, but in Canada, where many subject lines contain French words, it was impractical to test.
if my theory is correct, it follows that the more emails you have in your inbox, the more likely you are to have a problem.
None of the foregoing changes the fact that there is a major bug in iOS 18Mail, but maybe this will provide a temporary workaround for some people
Just confirmed with the developers at Fastmail that this is an Apple problem. The workaround for me is to use the Fastmail app. I'm glad we're getting confirmation from Apple too.
Re: "The moment I removed the special characters from the password my mail started coming in."
"The moment that I downgraded my security to make my password simpler to hack...to work around Apple's Mail bug..."
stephen boyle wrote:
...
Does anyone else with this issue on dovecot want to test that change? You would need to change the 'imap_capability' configuration parameter in the dovecot conf files. In my case i used imapsync in verbose mode to get the current default advertised capabilities. I then removed 'IDLE' from the string and entered the rest into the configuration file. For example:
imap_capability = IMAP4rev1 LITERAL+ SASL-IR LOGIN-REFERRALS ID ENABLE XAPPLEPUSHSERVICE AUTH=CRAM-MD5 AUTH=PLAIN AUTH=LOGIN
then reboot dovecot and reboot the mail iOS client.
I'm game to try, but have no idea how to do it. Google finds several inquiries, many of which have super-useful responses like "why do you want to do that?", and a few may have instructions, but they are not comprehensible to me.
btw, if I "telnet localhost 143" on my server, the response is as follows - so it's definitely advertising idle capability:
CAPABILITY IMAP4rev1 LITERAL+ SASL-IR LOGIN-REFERRALS ID ENABLE IDLE STARTTLS XAPPLEPUSHSERVICE AUTH=CRAM-MD5 AUTH=DIGEST-MD5 AUTH=LOGIN
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 !
Mine started downloading again after I switched off McAfee VPN.
If you are running a VPN turn it off.
If you are running a VPN turn it off.
After rebooting my iPhone I could finally read my IMAP mails again
Let's hope this solves the problem
I appear to have made some progress.
After upgrading to the full release 18.2 with no success, I:
there were a few initial errors which I put down to lack of bandwidth for downloading several GB of email, but it looks like I might have got rid of the annoying error messages, and email appears to arrive promptly when I force a check.
I’ll keep an eye on it, but it’s looking MUCH better. Fingers crossed.
(this was on my iPhone 15 Pro. I’ll see if the same fix works on iPadOS later)
To resolve this issue do this:
Go to settings - mail app - open the mail account you have problem with - incoming settings - IMAP Path Prefix — replace the greyed out / with a \ instead.
save = problem solved.
I also submitted a support request with my email provider (Fastmail) who were able to solve the problem for me and get me back up and running. I'm told it was an "IMAP protocol issue" that affected a very small number of users. Apple clearly owns the problem, but there may be a benefit to hitting up your email provider too. Worked for me.
Delete you present email account in Mail and reenter it.
Re-add your Hotmail account using the Exchange option.
The update to 18.1 has fixed my issues with mail and my wifi works
Error in downloading mail on IMAP after ios 18 upgrade
