POSIX 54 Error in Mail (iCloud Custom Domain)

Having the same issue with iPad OS 18.1

Definitely not happy about this, I hope that Apple fixes this problem soon.

Update: I chatted with a Apple support rep and had me trouble shoot it:

- turned off iCloud email in iCloud settings.

- force restarted iPad

- turned iCloud email back on in settings

Email is now working and the error has disappeared since!

If you are using a VPN turn it off.

I had the same issue after updating my software to OS18. Powered down my phone and back up, and it was resolved.

Today I reset my Network Settings on my iPhone 14Pro iOS 18.1 and also re-built my mailbox in Apple Mail on my MacBook M1 Pro. This seems to have fixed the issue!

I’ve been getting this error, I found that coming off WiFi and using 5g to update my mail then going back to WiFi clears the error.

Using SE 2020 version and Rackspace. I’ve tried everything to fix issue. Here’s the only thing that worked: Quit Apple Mail and Restart iPhone. This fixes issue for a few hours or even a few days. If I get error code again, just restart again. It should be fixed in next iOS update.

Turning off wifi worked. If problem recurs what next. Thx.

It's on Apple Servers and it can only be fixed by Apple. I have read that Apple Engineers know about it but no time line for a fix.

My only recommendation would be to remove the email account and then force restart your device, as I did, then readd the email account, as it might help and follows a similar process.

Good luck!

I had the same experience. Turned off WiFi and my Gmail emails came through on 5G right away. Maybe will have to do that until Apple fixes the bug?

Yes, the same thing is happening to me. I see that you're connecting to secure.emailsrvr.com, which is Rackspace. I also use Rackspace. And this just started with ios 18. Happens to both me and my wife. I reject the other replies in this thread. I don't think this has anything to do with iCloud servers since connecting to the Rackspace servers uses SMTP and does not utilize iCloud. Also, this has nothing to do with texting, RCS, or anything else people seem to be bringing up in this thread.

With me, its intermittent. If I ignore the error, eventually I stop getting it and it works fine.

I've reported it to Apple. I'm also going to report it to Rackspace since it may be an issue with one of their SMTP servers. Actually, I suspect this is the most likely scenario.

It may be a coincidence, but so far, I only seem to be experiencing this when using WiFi. I tried a few different WiFi networks and it happened on all of them. I haven’t seen the issue on cellular.

I’m home and just turned off Wi-fi on my phone and Mail connected to gmail accounts immediately. Got all of the emails I was missing. Thanks!

Yes I'm receiving this error message;

"The mail server "secure.emailsrvr.com" is not responding. Verify that you have entered the correct account info in Mail settings.

Network error (POSIX 54)"

Still having this issue. Only Occurs on wifi. Switching to Mobile Data clears the error but only until you go back on Wifi. 15 Pro Max Running 18.3