mediacombb.net email servers, SPF and DMARC

mediacombb.net publishes 2 MX hosts, all at priority 10, so senders spread mail across them.

5 other domains we checked on the same day also route mail to hosts under cloudfilter.net, with different records from mediacombb.net: brighthouse.com, eircom.net, mchsi.com, bresnan.net and midco.net.

The record on 5 November 2026 was v=spf1 mx include:_spf1.mediacombb.net include:_spf2.mediacombb.net include:_spf3.mediacombb.net include:_spf4.mediacombb.net ~all.

In plain terms, it delegates to _spf1.mediacombb.net, _spf2.mediacombb.net, _spf3.mediacombb.net and _spf4.mediacombb.net. The top level uses 5 DNS-querying terms; SPF allows 10 in total including nested includes (RFC 7208 §4.6.4).

It ends in a soft fail (~all): mail from unlisted servers should be accepted but treated as suspicious.

The record is v=DMARC1; p=none; rua=mailto:[email protected]; fo=1; adkim=r; aspf=r; pct=0; sp=none.

p=none only asks for reports; failing mail is delivered as normal, applied to 0% of failing mail.

Aggregate reports go to mediacombb.net, so the domain's owner sees who sends mail as @mediacombb.net.

Our checker treats @mediacombb.net like any domain: syntax, MX, disposable and role checks first, then a made-up address to rule out a catch-all, then your address at RCPT TO, disconnecting without sending. We have not published a test of how mcc-east.mx.a.cloudfilter.net answers for @mediacombb.net, so we make no claim here about whether single mailboxes can be confirmed; each result carries its own reason.

DNS tells you where mail goes, not whether one person's mailbox still exists. For a list, run the whole file through a verifier before you send: invalid rows come out, risky rows (catch-all, unknown, refused) go in their own segment, and valid rows are safe to mail.