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,...
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,...