Hi I am checking my SPF status at firstname.lastname@example.org and I get a softfail. from the header info it listed at the bottom of the reply it looks as though it is receiving my IP6 address not my IP4 and I presume using this with my txt record. Header info Return-Path: <email@example.com> Received: from srv.testserver.com (2001:888:888:888::66:5100) by verifier.port25.com id h6skbm11u9cp for <firstname.lastname@example.org>; Sat, 29 Mar 2014 16:10:35 -0400 (envelope-from <email@example.com>) Authentication-Results: verifier.port25.com; spf=softfail (SPF-Result: SoftFail) txt record v=spf1 a mx ~all I am also currently having fun with gmail blocking and had read that gmail were doing this to IP6 connections. My question is if this is to do with using IP6 how can I get my system to only use IP4 and is that a good solution or should I be doing something else. The server is running Debian Wheezy, Courier, ISPconfig 18.104.22.168, Postfix.