Where to go to see if the IP is blacklisted as a SPAM

GMail and others will frequently blacklist a block of IP addresss in addition to the IP they are blocking. Getting an IP address white listed by Google, Yahoo, etc. is a tedious and slow process. And it is different for each email provider.

Here are links to the 4 major email providers mailing guidelines:

• http://postmaster-us.info.aol.com/Postmaster.Guidelines.php
• https://support.google.com/mail/bin/answer.py?hl=en&answer=81126
• http://mail.live.com/mail/policies.aspx
• http://help.yahoo.com/l/us/yahoo/mail/postmaster/basics/postmaster-15.html

It is possible, that the gmail Services is using a domain blacklist for incoming mails. In this case, the blacklist entry will effect your mail delivery.

But other reasons could be:

• The mail looks like spam ( only html with one image without text for example )
• The originating mailserver is blacklisted.

To track down the sending system, you just have to look at the received trace in the mailheader of the bounced mail, and watch for the last public ip, not from gmail.

I assume that the mail is not send by any system under your control, or i misunderstand your question in that point.

To look up all blacklist, you could use http://multirbl.valli.org/