[bhauer]

Yes, it is. Virtually all normal SMTP servers will re-try e-mail delivery several times spaced over at least several hours before rejecting delivery with a notification back to the sender.

I have run my own e-mail server for about 17 years, originally from my home and more recently from a data-center where I have co-located my server. Admittedly, when I had my mail server at my home, I would suffer outages long enough to miss e-mails when I needed to do something as severe as work on my home's electrical panel or move. But generally speaking, a momentary glitch in network connectivity would not result in lost e-mail. Since moving my server to a data-center, the only downtime I had was when I needed to replace a disk.

As the above paragraph suggests, I am strongly in favor of people running their own mail servers and moving away from the presently-popular centralized Internet, back toward a decentralized model. This device isn't for me, and probably isn't for several of us here, but it's precisely the kind of thing I'd like to suggest to other people who would not otherwise be comfortable running a mail server.

I know a lot of programmers who shiver at the thought of managing their own servers, and I feel that's a regretful situation for the Internet at large. It suggests two things: (a) many programmers fear servers, which I don't think is healthy and (b) insufficient R&D has gone into making infrastructure easier to manage. After all (a) is a rational fear given the state of the art in many cases. It can in fact be quite difficult to set up a mail server (although once setup, most are pretty hands-off). It should be much easier to navigate through the settings and have a nearly out-of-the-box configuration that is sane and avoids the most common pitfalls.

Aside: Incidentally, I found that even mainstream ISPs like AT&T will unblock port 25 if you call them up and explain you are running your own personal mail server. When I moved to AT&T country, they did exactly that with no questions asked.

[mbrock]

Great comment.

As for programmers fearing servers: all the mail servers I've tried are almost incredibly byzantine, making them stressful to configure and hard to understand.

My brother got tired of this and wrote a functioning and mostly conformant SMTP server in less than 50 lines of bash (using djb's tcpserver and delivering to maildrop).

As far as I'm concerned, all the configuration I can ever imagine needing for a simple SMTP server could be specified with like max 3 command line switches.

So yeah, I think it is a somewhat rational fear, and I don't understand why everything seems so amazingly complex.

[jlgaddis]

FWIW, OpenSMTPD is extremely simple to configure and get up and running. (I don't use it other than as an "outbound-only sender" but the configuration file is very readable and simple).

[c22]

To add to that I've found OpenBSD in general to be extremely easy to administer. Most configuration is straight forward and no more complex than necessary with very clear documentation.

[mbrock]

Cool, thanks.

[pavel_lishin]

> many programmers fear servers, which I don't think is healthy

I fear the consequences of doing it badly or wrongly. It's like building my own car - I could probably do it and drive it around for awhile, and if nothing goes wrong nothing would go wrong - but if something does, suddenly it goes very badly indeed.

[fche]

"Since moving my server to a data-center, the only downtime I had was when I needed to replace a disk."

By the way, there exist backup MX services - commercial or self-made, which would give you 100% incoming-mail uptime but without having to move or copy your server to a data center.

[jlgaddis]

Some hosts are doing away with backup MX hosts (including me/work) simply because a) any sane sender will retry for a period of at least several hours and b) sending via the backup MX is a common way for spammers to (attempt to) increase the chances of their mails getting delivered (e.g., due to lack of/decreased filtering on backup MX hosts).

[bhauer]

Thanks for the note! I'll definitely keep that in mind next time I evaluate my hosting environment. I expect to switch to a different data center eventually, and that would come in handy.

[vidarh]

Usually they will retry for days. 4 days is conventional, and it's rare to see less than 24 hours... So you're right, it's a rare concern.

And of course if that's an issue, it doesn't take a huge amount of effort to run two - the secondary only needs to run the MTA with sufficiently longer retry intervals for passing mail on to the primary to give you whatever safety margin you'd like.

People seem to forget that e-mail started out in an environment where not all recipient hosts could even be expected to be online all the time - there's decades worth of solutions for doing store and forwards for hosts with intermittent connectivity, so dealing with failure of an MTA is easy.

My big issue with running my own mail server these days, though, isn't the inbound e-mail but deliverability of outbound e-mail. These days I'd be inclined to pass my outbound messages through somewhere like Sendgrid or Mandrill (at a cost) to let someone else deal with the deliverability problem.

[spin]

I know a lot of programmers who shiver at the thought of managing their own servers...

I used to be a sysadmin; now I'm a programmer. I love to host my own webservers and the like. But email? That's just a never-ending uphill battle. Between spam, and whitelists, and botnets constantly port-scanning your server (hope I've got all the latest patches, etc..).

For me, GMail solved this. GMail solved spam, and hassle. (At the cost of all my privacy being in the hands of a for-profit corporation.)

[benedikt]

How do you authenticate your mail clients with your SMTP server? Do you use the same SMTP server for incoming and outgoing mail?

[bhauer]

Yes, same server for inbound and outbound.

[benedikt]

Do you have a smartphone connected to this setup? Do uyou use a password over SSL to authenticate your email clients?

[bhauer]

Yes, and yes, I use SSL and a password to authenticate the clients. I'm curious where this is going. :)

[benedikt]

I'm just curious how others have their setup. :)