554 5.1.0 Sender denied

[EQ Admin]

Hello,

Did you get the error 554 5.1.0 Sender denied ?

The block could have happened for a variety of reasons including :

• Email sent From: an invalid domain name
• The email address is blocked
• The entire domain portion of the email address is blocked
• The IP address is blocked
• The IP address is listed in an RBL

To resolve the problem try contacting support at the destination to find out why the email was denied.

If that's not possible you can try to figure it out by checking your IP address for blacklistings.