Mehr kann man gegen den Mißbrauch der eigenen Maildomain kaum tun,

den­ke ich jedenfalls:

~$ host -t spf sokoll.com.
sokoll.com has SPF record "v=spf1 mx -all"
~$ host -t txt sokoll.com.
sokoll.com descriptive text "v=spf1 mx -all"
~$ host -t txt 20131231._domainkey.sokoll.com.
;; Truncated, retrying in TCP mode.
20131231._domainkey.sokoll.com descriptive text "v=DKIM1\; p=" "MIICIjANBgkqhkiG9w0BAQEFAAOCAg8AMIICCgKCAgEAngk88Vza1xgQMl3NW1Ok" "sre+WnNcFIsCO5PIgR+Q9P/+o+mt3JkEzjBXv10/WDeYtzH6wuo/7dzyOoU2VuUt" "1Nf+7ae0KnMgAPH0MYiAJ7PcU4q9HOz/xbHqvmI4fBoWg7/0334okQPrKrWls/GC" "Jw2ghPJ7ktjD+rxYWgWiTG8jHWxvjyJWBo6oC6f9fxDxKF0SmMTzeRyEjVH7He94" "kNbvZX2xGu9rVRY8Mi5daTuAGFbpKJrAEDEWlLJmM6eNTSJ+tMl9VGsUQb0w3cAZ" "Im6r3LtLPAXbbBfIKMNONaRHVghgH+RTuTW3NQLemS7E84xdBfpAGpYWAZHmKwU5" "FJI35lUyke7GZClMdnzMlD5FeZKPRTfLir4kihgw4NhwxPQw53yTM0BZgAwqZtnW" "56psHdT6U4X5dPPFd4GZ1OaF2VzwLII2OG9w3NddgytoUVc3OKbwkjtulLJw6aBQ" "9hjxPaTGIPr4pPGmFY7nqFhAwzhirHYO0ioSUTX6LMWPmrpvAiGhpdcelwDkLsx1" "WTV5rEKmzKNPg8wDAePxgcWoO91Z6I2Bza5vUxR4/b2S8dgi7V5M5PhkA9DSd0Dy" "Pc0RAjqfr/oUsXUrru9bxG1/bGSJY8ivf9tOp5LJQxjtpHuTjMURe1uUeeNUJwlJ" "23WQdyk/X8ppgNXnuT4/AwMCAwEAAQ=="
~$ host -t txt _dmarc.sokoll.com.
_dmarc.sokoll.com descriptive text "v=DMARC1\; p=reject\; rua=mailto:dmarc@sokoll.com\; ruf=mailto:dmarc@sokoll.com\; adkim=r\; aspf=s\; pct=100\; rf=afrf\; ri=86400\; sp=reject"
~$

DMARC ist heu­te dazu­ge­kom­men und — hal­lo Flo­ri­an — GRÜN! 😉