Diagnostic-Code: smtp; 553

We started getting bouncebacks when emailing our IT person last week. He has spent hours on the phone trying to resolve this. The case got moved to Tier 2 but no one has called him back.

Diagnostic-Code: smtp;  553 5.3.0 69.252.207.30 Your message was rejected for possible spam/virus content.Please ask your email provider to visit http://emailadmin.registeredsite.com for resolution.