Server Fault is a question and answer site for system and network administrators. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I know this question is a bit vague for SO, but I'll try to get it to the point: I want to get a better understanding of mail servers and the SMTP protocol. There are quite some products (sendmail, postfix, exim, ...) with HUGE documentations. And there are RFCs. But is there something in between? Some overview how real world mail sending and retrieving works?

I think about setting up my own mail server (or even implementing one using twisted), but my feeling is, that all those products solve problems I don't even know they exist. But I don't just want to install some software. I want to understand what's going on. Where do I start?

share|improve this question

closed as not a real question by Greg Askew, HostBits, Jenny D, mdpc, Dennis Kaarsemaker Jun 9 '13 at 20:07

It's difficult to tell what is being asked here. This question is ambiguous, vague, incomplete, overly broad, or rhetorical and cannot be reasonably answered in its current form. For help clarifying this question so that it can be reopened, visit the help center.If this question can be reworded to fit the rules in the help center, please edit the question.

Achim, in addition to v.good ideas by RobM and Jenny D, please set up this server either in an isolated environment or behind a solid firewall. Even 5 minutes in the wild wild Internet is enough to get a non-hardened server hacked (although most distributions AFAIK provide fairly conservative and safe defaults). – Deer Hunter Jun 9 '13 at 17:27
I second Deer Hunter's comment and am embarrassed that I didn't mention that. – Jenny D Jun 9 '13 at 18:01
Likewise- very good point – RobM Jun 9 '13 at 19:47

I think it's hard to look at "real world" examples without diving into a package and some of its documentation. I really would suggest setting up a Linux distro, installing something like sendmail (lots of documentation available, lots of options, lots of examples of "turnkey" installs) and playing with it.

share|improve this answer

I will, as usual, recommend an O'Reilly book. Specifically Programming Internet Email. There are also books about various specific implementations, e.g. Postfix, qmail or sendmail, but at this point I think you want something about email as such rather than any particular platform.

The RFCs you want are primarily RFC5321 and 5322.

And I second RobM's suggestion to set up your own server. I personally wouldn't choose sendmail as my first mail server, but that's very much a matter of taste.

share|improve this answer

Not the answer you're looking for? Browse other questions tagged or ask your own question.