7th August 2013
SPF is nice for protecting your mail server from spam, but sometimes there is a need to bypass SPF checking. For example, if you rely on 3rd party servers to do spam protection for you
- MX records point to the spam protection mail servers, which then
- connect to my server and deliver (hopefully spam-free) mail.
Problem: some senders (like last.fm) do have proper, strict SPF records. Tumgreyspf on my server then rejects emails relayed through the spam-protection service.
If these spam protection relay servers are the only which send mail to your server, then it makes sense to fully disable/uninstall tumgreyspf. Putting tumgreyspf into the permanent “learning mode” (set
defaultSeedOnly = 1 in
/etc/tumgreyspf/tumgreyspf.conf) may not fix the SPF problem described above, as SeedOnly seems to only affect greylisting, and not rejecting unauthorized senders.
Solution: whitelist relay server IPs.
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