Bug in Automessage plugin – where to submit a patch?

The Automessage plugin has a tiny bug in the sent messages. If viewing the sent messages in HTML format, the markup is processed as expected and all is well. However, if viewing in plaintext format, the markup is displayed with the message and it looks unprofessional. The markup should be removed from the plaintext version, but simply stripping tags will remove links instead of plaintext'ing them, so it will require a bit more work than that. I will probably write a patch this week – can it be submitted for inclusion in the plugin core? If so, how? Is it worth any site participation points? Thanks.