[Pkg-exim4-users] exim4 and forwards breaks mails from gmail

[Adi Kriegisch]

Hi!

> I am seeing the following problem:
> * Debian/squeeze, exim 4.80-7+deb7u on my own server
> * some emails are forwarded with .forward mechanism to 
>   a server that checks spf
> * mails forwarded are rejected with
> >     (ultimately generated from norbert at preining.info)
> >     SMTP error from remote mail server after RCPT TO:<preining at logic.at>:
> >     host tuvok.kom.tuwien.ac.at [2001:629:1004:11::25]:
> >     550 5.7.1 <preining at logic.at>... Mails from 'gmail.com' are not accepted via foreign mailservers like [IPv6:2001:4b98:dc2:41:216:3eff:fe7e:b079]!
> 
> According to the respective mail admins at the rejecting server 
> (I have good contact with them), they are just following strictly
> the spf records of google.
Yup:
host -t txt gmail.com
gmail.com descriptive text "v=spf1 redirect=_spf.google.com"
host -t txt _spf.google.com
_spf.google.com descriptive text "v=spf1 include:_netblocks.google.com
include:_netblocks2.google.com include:_netblocks3.google.com ~all"

~all -> softfail (from the specs, 'softfail' should cause a mail to get an
increased spam score or something like that, but refusing to transport is
a valid possibility too)
 
> Does that mean that gmail *cannot* be forwarded?
right. At least not reliably.

> Is this a limitation of exim(4) in squeeze, is there anything that
> can fix this problem?
No. You just hit a point where SPF is broken.

-- Adi