I am running a mailserver under
example.com that serves emails for a couple of domains. As my server does not have a mailbox, all the emails it receives are forwarded to particular Gmail accounts. To prevent the SPF from these emails from becoming
softfail, I installed PostSRSD to rewrite the mail header so that all of the forwarded mail comes from
example.com and the SPF passes.
Now, when I look at the message source for my emails (across all my hosted domains), everything looks great. All forwarded mails pass SPF and DKIM. But when the DMARC report for my virtual (non-
example.com) domains come back, I get this:
<policy_evaluated> <disposition>none</disposition> <dkim>pass</dkim> <spf>fail</spf> </policy_evaluated>
A Google search tells me that the SPF fails because of the PostSRSD rewrite. But in
<auth_results>, the SPF record is checked against
example.com (despite it being a DMARC record for, say
domain.com) and it passes!
<auth_results> <dkim> <domain>domain.com</domain> <result>pass</result> <selector>mail</selector> </dkim> <spf> <domain>example.com</domain> <result>pass</result> </spf> </auth_results>
If I leave my PostSRSD configuration as it is (i.e. emails from
domain.com sent from my mailserver continues to be rewritten to
example.com emails), I am concerned that it will affect my mailserver's IP reputation. Will it? If it does, I will have to mess around with PostSRSD to not rewrite my virtual hosted domains.