Does anyone know how this compares to Lamson (which has been around for quite some time) ?
Switchboard doesn't have any direct connection to SMTP. It monitors changes in your mail store using IMAP IDLE and issues events to workers which can then do basically whatever your heart desires.
(btw, we host our switchboard mailing lists on librelist.com which is a showcase for Lamson. cool project)
Additionally, there is Apache James (Java) which does something similar.
I'm not super familiar with Apache James, but it appears to be a mail server with pluggable components. Switchboard fits in as a layer between any mail server that supports IMAP, and its version of pluggable components [processes connection over the interface].
Thanks, this really helps us see where the documentation needs to be improved :)