On Oct 30 2004, 6:17, Vintage Computer Festival wrote: block The addresses blacklisted in You don't have a Class C, you have a block of 8. Looks like a DSL to me :-) In fact, the netblock which your addresses are part of *is* used for DSL lines, including dynamic ones, as far as I can see -- and the netblock as a whole is bigger than a Class C. from address? It's not in the obvious places like MAPS, so short of asking Google for all the blackhole lists, your best bet is to ask one of the sites that's blocking your mail. It could conceivably also be something to do with your broken DNS. The name servers don't return reverse lookups, and don't list an MX record. If you're running your mail server from a DSL line, that's the risk you take. It's too easy for spammers to take a short-term contract, get an address, abuse it, and disappear before the ISP can do anything about it. It's also common for inexpert users to misconfigure SMTP servers to be insecure in a spectacularly large number of ways. The easiest way to counter such problems is to list dialups and dynamically-allocated IPs (or the blocks they're in) in one of the DULs. Often the address space owner will do that. You could try asking Pac Bell if they have. The proper way to do it is to have your mailserver talk to a "smart host" that is well managed and hasn't ended up on a blackhole list. If you're bothered about the possibility that it might go down at a time beyond your control, and you use a recent version of sendmail, you can specify a fallback smarthost, I think. You ought to upgrade anyway, what you're using is fairly old [wonders if he should hide his own headers on this email ;-)]. Several ISPs will let you buy mail relay rights for very little money, and you can use SMTP AUTH to be able to talk to servers that know you, even when you're relaying through them. -- Pete Peter Turnbull Network Manager University of York