I wouldn't do the mail in a trigger but rather a stored procedure and then create a job to run the procedure every 5 minutes or so. That way when (and notice I said when) you have SQL Mail hang then your table won't get locked up. Just my two cents.
The trigger would be great to populate a "notices" table that would have information like Mail recipient, Message, Subject, etc. You may want to consider looking at the variables used in xp_sendmail and creating your table "notices" to be similar in style. Then your procedure could loop through this table to send out the notices on the schedule mentioned above.
If you would like an example, let me know and I will put something up.
Hope this helps.
“He is no fool who gives what he cannot keep to gain that which he cannot lose” - Jim Elliot