It seems that either DigitalOcean's DNS resolver is blocked by Spamhaus
or they started proxying requests through a public resolver which is.
Either way the error response is causing all mail to be rejected, so
pending a solution there will just have to be a bit more spam for now.

This was added dynamically from a config map to the previous monolithic
image to avoid updating the image. Now it can be added properly to
a versioned deployment.

A new check will be added later, either with a milter microsevice or
a policyd microservice. Either way it needs to be developed first.

Dovecot no longer has even any knowledge of SSLv2.

Fixes: #15

Until the client IP addresses are available (by implementing an L4
ingress controller?) these filters will need to be disabled. Here comes
the spam…