One week after I sent my original query, I’ve gotten no response at all from two of the three banks in question, and no response from the unsigned message I wound up sending to Bank of Montreal. Nice work, guys.
I’m going to try again, unsigned to all three this time, and at Mike’s urging, add President’s Choice Financial, even though they are run by the same bank that made me start looking for alternatives.
Update: President’s Choice and Citizen’s Bank have replied, the former with a partial answer and marketing spiel, the latter with a note that my message was forwarded to their website team. (Oh, and I got the standard automated non-response from BMO, but no followup yet.)
I guess that answers my question about signed e-mail….