Thoughts on qmail upgrade/replacement?

[Matt Simpson]

I'm currently running qmail on FreeBSD 9, which goes unsupported
12/31/2016. Shortly before or after 12/31, I'm probably going to
upgrade to FreeBSD 11, which is scheduled to be available by then.
That would be a good opportunity to make changes to my email
infrastructure, if any such changes are necessary. So I'm
contemplating what changes, if any, I need to make.

One possibility would be to completely abandon qmail, and move to
something more "modern". But I'm not convinced there's a better
system out there. The most popular alternatives seem to be Postfix and
Exim. As I read comparisons, it seems that the biggest complaint
against qmail is that it is "quirky" and difficult to configure. That
may be true, but at this point, I'm familiar and comfortable with its
quirks. The simplicity of another system might be outweighed by the
learning curve involved in translating my qmail configuration.

If anybody wants to suggest alternatives to qmail and why I should
consider them, I'm happy to listen. But, since this is a qmail group,
I'm mainly looking for suggestions about what to do with/to qmail if I
decide to keep it, which I probably will.

I'm currently running qmail 1.03, patched with John Simpson's combined
patch. Spam control is handled by spamassassin, invoked via simscan
as a qmailqueue frontend, so spam is rejected in the SMTP session
instead of bounced later.

I'm happy with the way this works, and there's a lot of merit to "if
it ain't broke, don't fix it". But I'm slightly bothered by the lack
of IPV6 support. I don't know if this will ever cause any real
problems in my lifetime, but I'd be a little happier if I had an IPV6-
compliant mail system.

My tcpserver is IPV6-capable, and accepts incoming messages from IPV6
addresses. Qmail doesn't seem to think the IP addresses in the
headers are valid, but that doesn't seem to bother it. And of course
there is no outbound IPV6 support in qmail-remote.

I like the concept of using FreeBSD packages/ports whenever possible.
The current port version of qmail seems to be netqmail-1.06. I think
it has IPV6 support, but I'm not 100% sure about that, and I don't
know whether it has other features that I need.

I don't think the JMS patch will apply to netqmail-1.06 without
modification. Does anyone know if there is a version of the JMS
patch, or a patch that provides similar features, that will apply to
netqmail-1.06? Or another single patch for qmail that has some of the
JMS features and IPV6 support? I think the features I need most are
SMTP recipient check, SMTP AUTH, and inbound/outbound TLS. I'm using
some other features of the JMS patch that are nice to have, but I
could probably live without them.

But if I have to do a lot of patching to the FreeBSD qmail port to get
what I need, I'm losing the advantage of using ports, and maybe I
should just consider another more holistic system.

That seems to point me in the direction of Erwin Hoffman's s/qmail.
It seems to provide all the features I need. Is anybody else using
that? Any good or bad experiences to share?

Anything else I should be thinking about? Anything you wish you had
done when you set up qmail, but it's too late to change now? I'm not
quite starting from scratch, but pretty close to it, so I've got lots
of room to play.