Hi, I'm recently running into a probs with hotmail, from my sending server, every emails sent out to hotmail got bounced back and this is what i found in the log: M43120/xx.xxx.xxx.10:5050/host1.xxxx.info;O1;i270;o84;E4;T1320161358;18.104.22.168;[email protected];550 SC-001 (COL0-MC3-F21) Unfortunately, messages from xx.120.xx.xx weren't sent. Please contact your Internet service provider since part of their network is on our block list. You can also refer your provider to http://mail.live.com/mail/troubleshooting.aspx#errors. any fellow MF member's advice how to unblock it? Thanks in advance!