How to resolve 'HELO/EHLO outbound.qs.icloud.com is not matching your DNS configuration' error in iCloud Mail?

This error typically occurs when the hostname in your email server's EHLO greeting doesn't match the forward-confirmed reverse DNS record for your server's IP address.

To resolve this, you may need to contact iCloud Support or the email provider to verify and adjust the DNS configuration on the server.

This is doing my head in now. While connected to my home network I'm unable to send from myself@icloud.com to any ntlworld.com or virginmedia.com address. I just get the error in the opening post, not straight away, but after a number of hours. I have several icloud addresses and I've tried both the main address and the aliases and the result is the same. I've tried everything, restarts, reboots, altering mail privacy/IP hiding settings in iCloud, turning private relay off, all to no avail. If I tether to my phone and use mobile data (or just turn off wifi from my phone and send from there) it works fine, just not while I'm connected to my home network, which is a Virgin Media connection.

One thing that does work....if I just go to iCloud.com on the web and send the mail from there, it works, even while I'm connected to my home network. I'm not sure why that gets around it, but it's hardly convenient as I'd rather just use the Mac Mail app.

I am getting the same trying to send emails from my iPad and iPhone over WiFi to my ntlworld email address as is my wife. I have tried sending from my phone with WiFi off with the same results, email undelivered with same message some hours later…..

Is that email provider called Ziggo by any chance?

Thanks. This is very useful to know. I just confirmed that sending using webmail from iCloud.com avoids the problem.

I have the same problem. So i did a view test with dmarctester.com.

From my iphone and select my own domain e-mail everything is ok and all records (spf,dkim and dmarc) are ok and the e-mail wil pass.

from my outlook client you need to send the mail as your own e-mail adres, when you use your icloud.com adres and send it on behave it wil fail anyway.

From my own domain adres it gives an error on the spf and dmarc records. But the DKIM is ok. So the overall wil pass.

I checked all my DNS settings and they are ok (v=spf1 include:icloud.com ~all and v=DMARC1; p=quarantine; fo=1)

There seems no problem, but spf wil not pass. Is there a problem with the spf of Apple? is it incompleet?

The mail from my outlook client uses the Host p-east3-cluster1-host10-snip4-10.eps.apple.com

Do you have all the same problem?

sorry, my testing and all the right settings dit not work, stil have a bounce back😬:

host mxin10.ziggo.nl[84.116.6.2] refused to talk to me:

421 EHLO

MXIN201 Your HELO/EHLO outbound.qs.icloud.com is not matching your

    DNS

configuration p-east3-cluster2-host11-snip4-1.eps.apple.com

psrc=57.103.87.232

Same issue here

'... refused to talk to me: 421 EHLO MXIN201 Your HELO/EHLO

   outbound.qs.icloud.com is not matching your DNS configuration'

Been sending to the same address for years and I haven't changed anything my side.

Any help would be great cheers

I've got the same problem and error and it's just started in the last 3 or 4 days I think. I cannot send from my iCloud e mail address to any ntlworld.com e mail address, so messages to my customers and family are being bounced.

Exactly the same here.

can not send from iPhone to my 3 virgin emsil addresses over WiFi.

I can send with wifi off though using data though.

I can also send to gmail no problems regardless of WiFi on or off.

this has only happened since latest iPhone upgrade to 18.4.1 so This is an Apple problem!!!!

I can also receive Mail on all my emails on my mobile.

Same here getting the exact same problem since 18.4.1 upgrade.

can only send to Virgin/not email with data.

i can send to gmail no problems.

I can also send from any email to my phone.

all outward Mail I have to use data only which I forgot to.

!!! PLEASE FIX THIS APPLE SINCE YOUR LAST UPDATE TO 18.4.1 !!!!

That’s very good to hear. I surmise that there was something in the recent 15.4.1 update which caused this problem, and rebooting the router caused it to re initialise to work with the change.