PUBLIC MARKS from camel with tag benchmarking

To test and benchmark several common SMTP servers for Unix. This is inspired by the work done by Matthias Andree at his Postfix vs. qmail - Performance page. His information, while likely still highly relevant is based heavily around file system I/O and not overall performance of the MTA. Additionally, more MTAs and OSs will eventually be tested here.

PHP Bench

When benchmarking, we can use simplistic tools such as ApacheBench, but sometimes we need more sophisticated probes to find out the "truth of the matter".