iCloud Custom domain via iCloud+ --> rejecting domain, some emails are not delivered

[macuros]

Hello,

I'm using iCloud+ with my own domain, I've set up all DNS records according to Apple. I can receive and sent emails via Mail app with my own domain and really like it.

But… sometimes my emails are rejected (especially sending to some official email addresses) for instance:

Remote-MTA: dns; mail2.gov.si
Diagnostic-Code: smtp; 554 5.7.1 <****@********>: Sender address rejected:
   Access denied

This never happens when I send from my actual iCloud email address via Mail app, only happens if I use email with my own domain over iCloud.

Yesterday I've just sent an email to my wife's Gmail, and she got this warning:

I'm not sure what can cause this. I've checked the settings from Apple for custom domain several times and I don't see any issue there.

Any help or guide will be appreciated.

Thank you.

 

[russell_314]

I'm not sure if it's what's going on here but I was listening to a podcast and they were talking about how some email services were blocking custom email addresses with common words. Like if my email was bicycle at mydomainname. They don't even go into spam but just fall into a black hole. This is not an Apple thing because they were using a different email service.

 

[macuros]

Hmm, yes, not sure either. It's just frustrating that you can't be sure if your email is delivered.