Ask HN: How to parse emails like TripIt?

Does TripIt write custom parsers for each potential email source (Expedia, Orbits, United.com, etc)? Or are they using some sort of parsing library that I'm not aware of?

I run a small CRM system for notary publics (notarycrm.com) and customers are consistently requesting the capability to forward scheduling emails (from banks/signing companies) into NotaryCRM. The idea would be that we'd parse the emails and add the signing to the customer's account - saving them a few minutes for each signing.

UPDATE: If anyone is particularly interested in helping me parse emails via SendGrid's Parse API, contact me - will trade your RRuby on Rails skillz for money. :)