MailScanner is simply alerting you to mismatched link in the message:
Your monthly wireless bill for account 999999999 is now available for review at MailScanner has detected a possible fraud attempt from "cwclick.cingular.com:8080" claiming to be www.cingular.com/mycingular.
The problem is, they said to go to www.cingular.com/mycingular, but the link under that text actually pointed to another part of the site at cwclick.cingular.com:8080/some-long-number
So, don't be alarmed when you see the big Red MailScanner alert. The filters are doing their job, pointing out possible attempts.
If you ever question a link in an email from your bank, or any other site that has to deal with finance, or even login information, don't click the link. Instead, manually type the address into your browser. You probably have your bank as a Favorite anyway. So, login that way.
It doesn't hurt to be a little extra careful. A little extra typing can help you feel assured you are on the correct website.