Thanks! You were correct. TS was not configured to send e-mail. Explanation for anyone else reading this: you enter the recipient e-mail address into the indicator for the alert, but TS also needs sender information in order to send an e-mail alert. The e-mail alerts tell you what pair it is alerting on (very helpful). If you are using it with another indicator (e.g. RSI), it does not tell you "RSI" in the e-mail alert, but it does tell you what value the line was crossed at (so you can deduce what it is alerting on if you also happen to have a line crossing alert set up on piece on the same pair).
The only problem now is this: I did a few limited tests with the indicator and found that it seems to alert for crossing under, but not for crossing over.
Thanks!