Modern mail is really really complex, also see this paper. To reduce SPAM there is a really fun set of different standards, which you should use on your domain; However, some of those (DKIM, SPF, and DMARC) lead to rather mixed results when you post on mailinglists.
More to the point, strict DMARC p=reject settings make your mails being dropped if the mailinglist does not do ARC and SRS, fiddles with headers breaking DKIM, and--of course--relays your messages from a host not covered by your SPF policy.
Sooooo... to prevent this issue, i have a domain with DMARC policy p=none and SPF ?all (and the occasional ML mailsending hosts added as well) with which i subscribe to mailinglists to get around that issue.
If you are annoyed by me posting from this domain, or would like an account for all your mailinglist needs as well, please feel free to drop me a line at tobias+web@reads-this-mailinglist.com..
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