IPs blocked by MessageLabs - Connection timed out

Hi,

We start using new IPs provided by OVH to host web sites and they seems to be blocked by many email filters and MessageLabs refuse any connection from them. Theses IPs seems to be used to send spam some month ago. The IPs are 54.36.200.48/28.

Some logs :

6B566A215     88331 Wed Feb 21 18:22:57  ***@cook-and-gift.com
(connect to cluster4.us.messagelabs.com[216.82.251.34]:25: Connection timed out)
                                         ***@hudsonjeans.com

67769A214     87713 Wed Feb 21 18:22:57  ***@cook-and-gift.com
(connect to cluster4.us.messagelabs.com[216.82.242.179]:25: Connection timed out)
                                         ***@hudsonjeans.com

The removal lookup page (http://ipremoval.sms.symantec.com/lookup/) see no problem. It may be a network issue (some firewall blocking any connection).

Some know who to contact to remove this restriction?

Regards,