Hotmail blackholing certain IP ranges ?

Does anyone have a clue why hotmail is appearantly blocking certain IP ranges ?

I provided a new server for a customer in his own IP subnet which is a part of a /20 we announce, but for some reason all mail sent to addresses disappears.

He has another server in a /24 we announce which is still part of another network and that works like a charm.

None of our subnets are blacklisted in any spamfilter I can find, so i'm a bit puzzeled on what's up here.

If any hotmail netadmin is reading this list, can you please check if is blocked in any way (It's part of originating from AS39556)

According to the mailserver logs all the mail is properly accepted by the hotmail relays, never to be seen again after that.

Met vriendelijke groet,

Jeroen Wunnink,
EasyHosting B.V. Systeembeheerder

telefoon:+31 (035) 6285455 Postbus 48
fax: +31 (035) 6838242 3755 ZG Eemnes


A quick check of those IPs shows that most don’t have rDNS records. Make sure the A and PTR records for the mail server match the hostname it is using in the outbound SMTP session.

Hope that helps,
Adam Stasiniewicz

I've had the same issue with hotmail when email originates from any mail sent from a server within that netblock is
properly accepted by hotmail, given a queue id, but disappears and is
never delivered.

if anyone from hotmail has a clue as to what's going on, it would be

thanks much ...