(Lo)cal (s)mtp (s)erver for (d)isposable (m)ail (a)ddresses
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A dumb smtp server and a dumb email viewer

The purpose of this project is to implement the software required to test an idea I had a few days ago. It contains, as stated, of a dumb smtp server which does not even store received emails and a dumb email viewer, which can only view mails received via UDP.

What's the idea?

I guess you all use some kind of disposable mail service to handle registrations for pages you don't really use and/or social networking pages. I recently had the idea of using my own computer as a mail server for that.

So I hacked a small script which opens a SMTP server and uses webkit to display incoming mails in popup windows.

It soon appeared to me that a useful benefit of this is that you receive emails instantaneously, even if you don't have your email program open and configured for IMAP push. This is particularly useful for Facebook. But then, if I use my computer as an email address provider for my Facebook account, they will soon comply to me that my email account does not work and/or forward me a bunch of mails when I switch my PC on. A better solution was to have the SMTP server itself run independently of my PC, e.g. on my router, and just silently drop mails when my PC is turned off.

An implementation of this idea is exactly what I uploaded here!

The programs


A server partially implementing the SMTP protocol. Cross-compile it for your router and install it there. For example, if you have a Fritz!Box and use Freetz, run

 freetz-trunk/toolchain/target/bin/mipsel-linux-gcc -lpthread -o dumb_smtpd dumb_smtpd.c

To integrate the binary with Freetz, copy it into the subfolder


of your Freetz trunk directory. (You'll also have to activate the own-files addon. You can do this by editing the static.pkg file in the addon directory) Afterwards, edit debug.cfg to have the binary start automatically by adding a line like

 dumb_smtpd 11025 <your (dyn)dns name> <your pc's ip in your lan> 12025

and configure the firewall to forward port 25 to port 11025 on the router itself.


This python script listens on port 11025/UDP and reads emails, assuming they end with a line containing a single period (like in the SMTP protocol). Whenever an email is completely received, a window is opened containing a webkit view of the mail, either decoded text/plain or text/html (with embedded images!) if available.

Put it in your PC's autostart!


I mainly placed this here in hope for some feedback:

  • Do you like the idea? What do you expect: That I will get overwhelmed by spam soon? (Luckily, it's easy and does not hurt to change a dynDns-domain-name ;-)) Or that this might just work out?
  • Do you have any suggestions or improvements?