In order for "not receiving returned mail" to be valid as a reason the account is not dormant, the statements must be sent by first-class mail and must request an address correction on the face of the envelope. In addition, the bank must maintain a record of all returned mail.
I assume you have this process in place if you are saying that you haven't received any return mail?
The reason I mention this is that at a previous bank, someone made the decision to remove the address correction request from the mailing envelopes and we didn't find out until it was time to escheat.
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