Re: Just how static is that IP address?

[Dan Jenkins]

Ted Roche wrote: > TDS is offering their business customers (well, at least this one) a > static IP address at what appears to be a fair price. I know that a > static IP is set in the network stack, and there's no need to run a > DHCP client, since the IP address isn't going to change. This opens > up some opportunities that we more challenging with dynamic IP > addresses. > > Here are my questions: how do the big email services distinguish > dynamic from static IPs? Is there a great big list somewhere listing > the 256^4-2 addresses? Is there a way I can determine if the address > I get is "really" static (if there is such a thing) or should I just > try to set up a email server and see if I can get through to > [EMAIL PROTECTED]? Having a number of clients running mail servers on both dynamic and static IPs, I've found only a few dozen mail servers which pay attention to the dynamic vs. static lists. YMMV. So, I add an exception for those domains and relay messages for them through a "more" static mail server. One of them (rr.com) also considers some static IPs issued to T1 lines and co-los to be too dynamic for them, since they reject email from several such locations with a "dynamic IP number not allowed" message. They also reject email from the upstream ISP's mail servers similarly - which are the "official" mail servers. I've given up on getting a resolution with them as they routinely ignore all emails on the topic. Obviously, at least one of the "dynamic IP" lists is wrong, which rr.com must use. The several TDS static IPs I've used have never been blocked so far. The most commonly blocked IP ranges are from the cable providers (Comcast, Adelphia, etc.). So, checking the "good" lists doesn't help entirely, since at least one bad list exists and you never know who uses it. -- Dan Jenkins ([EMAIL PROTECTED]) Rastech Inc., Bedford, NH, USA --- 1-603-206-9951 *** Technical Support Excellence for over a Quarter Century