As mentioned previously I have switched from using the gld greylisting implementation to policyd . I had originally used the version of policyd in the ubuntu apt repositories—mainly for ease of installation and maintenance. After reading the policyd mailing list it became very clear that it would be of great advantage to upgrade from the modest v1.55 release in the repository to the latest- v1.73. There are quite a few new features in v1.73 compared to v1.55:

• HELO check – blacklist hosts which use a random HELO
• Recipient throttling
• DNS based whitelists
• Blacklist sender (envelope)
• DNS based blacklisitng
• SSL and Compression on MySQL connection
• MySQL5 compatability

I cleanly removed v1.55 with ‘apt-get remove’; v1.73 compiled with no problems. One thing to remember is that while the README.txt tells you to use ‘gmake’, you in-fact substitute this command with ‘make’ on a Ubuntu system.