I have a small issue with email being rejected from some domains. Below is the error message i recieve.
We run SBS 2003.
There was a SMTP communication problem with the recipient's email server. Please contact your system administrator.
<mail.domainname.com.au #5.5.0 smtp;550 Service unavailable; Client host [IP Address] blocked using 88.blacklist.zap; Mail From IP Banned To request removal from this list please forward this message to email@example.com>
How do I verify that it my IP is blacklisted, as this only happens on some domains. I forward my email through a smarthost with my ISP . If i forward to delist@frontbridge it bounces.
Any help would be appreciated