My one gripe so far with the direction of this project (and 0.9 seems to push it even further in that direction) is that it makes heavy use of the to-field-as-command-interface style of interaction, e.g. "subscribe@somegroup.com," "confirm-list-324@somegroup.com," etc.
For me this just isn't a super intuitive way to interact with an application, and most email readers aren't really designed very well around typing arbitrary commands in to field. I was much more excited about the prospect of just typing text in the body as the means of interaction.
I also see this as more of a great extension to an existing application than a standalone application of its own. Maybe I just haven't looked far enough in to the documentation see how to make that happen easily.
I still dig the project and am keeping a close eye on it.
If you can say it in a regex (or lamson router match expression), you can use it to route. If you don't want to use commands-in-the-to-field, just write you handler so that it parses the body. Lamson doesn't make you use to-field-as-command-interface, nowhere is this style pushed. 0.9 leaves you completely free to choose your type of routing, more flexible than previous versions.
The reason to do it in the "to-field" is because it's easy to parse without having to read the whole body. Parsing an email body is far more complicated, you have to deal with, clients automatically adding signatures, advertising from free email providers, unwanted html markup,...
Python needs better email servers. I'm not sure this is the final answer, but it's nice that there's something other than the stdlib one, and the twisted one... neither of which offer a good total solution.
I've slagged on Zed once or twice, but the above sentence is pure gold.
I'll definitely give Zed this: he's willing to take it as he dishes it out.
Thick skin is a necessary trait for anyone who wants to change the world.
Kudos to Zed.