Re: [exim] exim4, gmail and 550-5.7.1

> > On 11/12/15 21:22, Robert Steinmetz AIA wrote:
> >> Any email to a gmail server is rejected with a 550-5.7.1
> >> error, basically requiring a ipv6 ptr record.
> > [...]
> >> Unfortunately our IP addresses are provided by our ISPs and
> >> they don't provide ipv6 ptr records.
> >
> > That's your basic problem; go beat up your ISP or move to a
> > better one - because, big-G will proceed in the future to
> > apply the same constraints to ipv4. My prediction; I have no
> > special knowledge. But "we're the phone company; we don't
> > have to care".

The last sentence hits the point. It's like that for a long time now
and likely won't change any time soon. I gave up on ISPs getting a clue
and consider them as access providers only.

It's not just reverse mapping. If providers don't care, their whole
address space block may suffer justified from bad reputation. Some ISPs
suddenly "protect" customers by funny restrictions. Running a reliable
service from a cheap access address causes too many issues over time.

I suggest to separate statically routed traffic from cheap access by
tunneling it. There are various very affordable tunnel/VPN providers
that offer static IP space with configurable reverse records. This has
the benefit of being able to change access providers as needed without
touching any service.

Michael