Hi,does anyone in here have Comcast? I have my own exchange 2003 host locally, but sometime having problem sending mail. I don't have any problem receiving mail. I checked with my ISP and they told me block 25 is not block. When I sent mail to couple of my friend from msn,yahoo and gmail, most of them doesn't go through. I have my own yahoo account and it went through fine. I also try sending to respond some job post and some went through and some not. This is the error message I got: blocked by ldap:ou=rblmx,dc=comcast,dc=net -> Comcast.net subscribers are not permitted to directly connect to this mail server. If you are a Comcast Commercial Services customer and need support, please contact support_biz@cable.comcast.com> In exchange 2003 >> outgoing mail>> smart host, I had added smtp.comcast.net. I still got the same problem. So do you think I might need to switch to other ISP that will need static IP? Right now I have DHCP. I also have acounts with dnsalias.org incase my ISP change my dnsalias will update automatically.

If it is a free mail account, the problem could be "POP before SMTP". Means, you have to retrieve mail before you send mails. And you need to login to that mail account with username and password, normally yourname@comcast.net and password. Paul