mu emails are being blocked

[tdbatch]

hi I have been having a lot of problems with emails to and from my domain, over the last week i have been receiving emails from companies such as hotmail, blueyonder, stating my emails are being returned

Rejected with: 550 DY-001 Mail rejected by Windows Live Hotmail for policy reasons. We generally do not accept email from dynamic IP's as they are not typically used to deliver unauthenticated SMTP e-mail to an Internet mail server. http://www.spamhaus.org

I have checked and my server is setup for smtp authentication, I have other domains on the server and they seem to be working ok.

any ideas?
Thanks

[rob]

Many large email sites such as hotmail, aol...etc use various SPAM filters to weed out potential SPAM sources. One common detection method is, as your error message indiciates, if your IP is dynamic - it is frowned upon. Often this can be enough for them to reject your outgoing mail, but as your problem indicates, it only seems to be affecting your particular domain out of several. Unfortunately, other than contacting and requesting the various services such as hotmail, aol...etc to see if you can go on their whitelist, you may need to fix the problem by rerouting your mail via your ISP's SMTP or another SMTP with a static route (outgoing mail service settings). Another option would be to try to obtain a static IP from your ISP (this generally costs however).

Your error message doesn't imply that it's to do with SMTP Authentication, and is an issue purely with AMS trying to deliver mail to external email sites.