If you run BIND
Paste this into your zone file:
fileblast.net. IN TXT "v=spf1 a mx ~all"
When a mail server sends a bounce message, it uses a null MAIL FROM: <>, and a HELO address that's supposed to be its own name. SPF will still operate, but in "degraded mode" by using the HELO domain name instead. Because this wizard can't tell which name your mail server uses in its HELO command, it lists all possible names, so there may be multiple lines shown below. If you know which hostname your mail server uses in its HELO command, you should pick out the appropriate entries and ignore the rest.
So this should also appear in DNS. You may or may not be in charge of the DNS for these entries; if you are, add them.
mail.fileblast.net. IN TXT "v=spf1 a -all"