can you please give us more details. Is it only one email address or multiple ones? A simple text email or rich text or HTML? Are we looking for a certain keyword in the email?
There's no built in email trigger functionality in UCCE. But you can certainly intercept emails when they arrive, provided you have a simple script that can do telnet - for instance, if your email server has got POP3 or IMAP access, I can imagine a simple Java application (JavaMail rocks ) that would connect to the email server, get the list of new emails, perform some text search (it may be necessary to distinguish "legal" emails from the ones that arrived by mistake, like spam).
I did a similar project a couple of years ago. A monitoring system sent an email, it created an issue in JIRA, and also rang our mobile phone saying something like "Major/Minor alarm at customer site XY".