Stamping out Gmail?

A Platinum Club mega-uber value reader in the Netherlands writes in with the following odd story. He attempted to send a message from his Gmail account to a friend who subscribes to UPC's Chello broadband service, and got the following failure message:

"This is an automatically generated Delivery Status Notification Delivery to the following recipient failed permanently: XXXXXXXXX.XXX@chello.nl

Technical details of permanent failure:PERM_FAILURE: SMTP Error (state 9): 551 Mail from your IP is currently blocked based on RBL listing"

If anyone out there has experienced similar incidents, please let me know.


UDPATE: A mega-forte uber-value reader writes in with the following insight:

"Some Gmail IP addresses have been intermittently going in and out of the spamcop DNSBL for many months. This is an effect of how spamcop works and something that people using spamcop to reject mail should know well. On the other hand, the world is full of morons, so some sites use spamcop to reject mail without understanding that it is designed to be an aggressive DNSBL. I have not checked recently, but some time ago even spamcop FAQ explained that people are supposed to use its DNSBL only for scoring. I see this as another case of stupid people getting what they deserve (and of Google being victim of the NIH culture and not being willing to implement proper countermeasures against the 419'ers)."