550 #5.1.0 Address rejected [WEBMAIL]

[erickoooo]

Hello, I recently set up my webmail addresses (e.g. admin@example.com) using Roundcube and everything was seamless.

1. I can send messages from the addresses
2. I can receive messages from Wordpress (i.e notifications of password changes etc)
3. HOWEVER, when I try sending emails to the address via Gmail and Yahoo accounts, they all fail saying "address not found" - Gmail in particular gives me the error code is the subject line of this post

Anyone with an idea how to fix this? I am really frustrated and my reseller isn't doing much to help. Any help with be highly appreciated.

Thanks All

[SKaero]

You most likely have some DNS or something else on the mail server side setup incorrectly. Try testing using https://www.mail-tester.com/ and it should tell you what is wrong.