Any SPF experts here?
 

I'm trying to create an SPF record, but the email system through which I send mail could send from any one of 8 different servers. They are named sorta like this:

server00.outgoing.domain.com
server01.outgoing.domain.com
.
.
.
server06.outgoing.domain.com
server07.outgoing.domain.com


When I'm forming my SPF record, can I just use a:outgoing.domain.com, or do I have to list them, one by one?

Have you tried generating a suitable SPF record automatically, using the tool at openspf.org? It's quite good, it might answer this question for you.

Yes, I have, but while using a:outgoing.domain.com is valid syntax, I'm not sure that it will work if I don't list out every possible server. And I don't want to just put it in as-is because it affects more than just my email address. I guess I could just list out every one of the servers, but what if they add more to the cluster? I don't want to have to keep editing the DNS if I don't have to, hence my inquiry.

Ah, fair enough. I'm afraid I don't know enough about SPF to be sure of the answer, but I did find this page, which suggests that wildcards can be used. I'm not sure that's what you're looking for here though. On another page it is suggested that you ask your ISP if they have SPF record that you can use via the "include:" option. Other than that, I can only suggest adding all of the servers to be on the safe side, and hoping someone who actually knows what they're doing finds this thread!