I administrate the domain [mydomain.com] which was until now only used for handling mail through Google Mail/Google Apps.
Now I added a server which should be part of the domain without changing the primary purpose. I want the server to be able to send simple administrative mail, so I installed and configured sendmail.
When I send testmails to another Google Mail address the mail gets through but I get this header information:
Received-SPF: pass (google.com: best guess record for domain of [myuser]@[myhost].[mydomain].com designates [myipv6address] as permitted sender) client-ip=[myipv6address];
Now of course I want the validation to pass without guessing but I have probably something wrong in my DNS record.
$TTL 86400 @ IN SOA [mynameserver1]. ( 2013101002 ; serial 14400 ; refresh 1800 ; retry 604800 ; expire 86400 ) ; minimum @ IN NS [mynameserver3]. @ IN NS [mynameserver2]. @ IN NS [mynameserver1]. @ IN A [myipv4address] [myhost] IN A [myipv4address] @ IN AAAA [myipv6address] [myhost] IN AAAA [myipv6address] @ IN MX 1 ASPMX.L.GOOGLE.COM. @ IN MX 5 ALT1.ASPMX.L.GOOGLE.COM. @ IN MX 5 ALT2.ASPMX.L.GOOGLE.COM. @ IN MX 10 ASPMX2.GOOGLEMAIL.COM. @ IN MX 10 ASPMX3.GOOGLEMAIL.COM. @ IN TXT "v=spf1 a:[myhost].[mydomain].com ip4:[myipv4address] ip6:[myipv6address] include:_spf.google.com ~all"
I can't find the error and would appreciate any help.