Minimal Postfix SMTP Proxy

Current version: 0.2.0 (24 Jan 2006) [src]

postprox is an SMTP proxy which copies an SMTP conversation between its input and another SMTP server, but spools the DATA portion to a temporary file and runs a specified program on it before passing it on to the output server - or outputting an SMTP error code instead if the content filter says so.

The design aim of postprox is to do only one job: proxy SMTP conversations and pass message contents to another program to determine whether to accept or reject the message. With this in mind, postprox is small and has a minimal feature set; its reduced complexity reduces the risk of bugs and security holes.

This software is distributed under the terms of the Artistic License.

Comments, bug reports, and patches gratefully received - please use the Contact Form.

If you liked postprox, please consider a donation: [Donate]

News

(1 August 2011)

• generous donation received from JRS Systems - thank you!

0.2.0 - 24 January 2006

• added $OUTFILE so filtering scripts can modify the email in transit
• use putenv() instead of setenv() for better portability
• capture IP address, HELO, sender/recipient for logging

0.1.0 - 11 August 2005

• changed command line syntax
• created testing framework
• fixed line reading after feedback from postfix-users mailing list
• created tests to throw long lines, dots, etc through the proxy

0.0.1 - 5 August 2005

• package created

To Do

Things still to do:

• make read/write line buffers independent of network buffers
• deal with disk full condition on spool file
• option for max filter message size, deliver if exceeded
• additional tests
• implement listen mode