mail kommt zurück

Wenn ich an gewisse Adressen maile kommt diese Antwort zurück, was heisst das und wie kann ich trotzdem ein Mail senden?

The original message was received at Mon, 18 Sep 2006 11:11:22 +0200 from 84-74-243-122.dclient.hispeed.ch [84.74.243.122]

—– The following addresses had permanent fatal errors —–
(reason: 550 62.2.95.247 does not pass SPF requirements for domain rebecca.romano@gmx.ch)

—– Transcript of session follows —– … while talking to mail.trentmail.com.:
>>> MAIL From: SIZE=4272
<<< 550 62.2.95.247 does not pass SPF requirements for domain rebecca.romano@gmx.ch
554 5.0.0 Service unavailable
Rebecca