To send mails, today some tests use msmtp and others our internal smtpc.py.
This works, but msmtp slows down the tests significantly, and smtpc.py
is also not particularly fast, and also has some limitations.
This patch introduces a new SMTP client tool written in Go, and makes
almost all the tests use it.
Some tests still remain on msmtp, mainly for client-check compatibility.
It's likely that this will be moved in later patches to a separate
special-purpose test.
With this patch, integration tests take ~20% less time than before.
This patch updates the shell scripts with some of the common best
practices, which should make them more resilient to unusual failures and
unexpected environments (in particular, directories with spaces).
Most of these were identified by shellcheck.
glog works fine and has great features, but it does not play along well
with systemd or standard log rotators (as it does the rotation itself).
So this patch replaces glog with a new logging module "log", which by
default logs to stderr, in a systemd-friendly manner.
Logging to files or syslog is still supported.
We should ignore the domains' case, and treat them uniformly, specially when it
comes to local domains.
This patch extends the existing normalization (IDNA, keeping domains as
UTF8 internally) to include case conversion and NFC form for
consistency.
This patch adds initial support for SMTPUTF8, which for now consists of just
advertising it.
We support most of it, but sending emails over SMTP requires further work, as
the SMTP courier does not support this yet (it's not in Go's standard
library). That will come in subsequent patches, along with IDNA handling.
https://tools.ietf.org/html/rfc6531.html
