"You must sign in to your account at least once every three weeks for it to remain active."

Nope, it's not the three-week rule. I've checked and re-checked my spam settings. Yet messages aren't getting through, even those sent in reply to mine. I missed an appointment today - something I hate to do - because I thought the provider had not replied to my inquiry. She had. I just didn't get it. Strange.

Actually, I've had problems sending from a hushmail alias to another hushmail account, for at least a couple of years.  That seems to be fairly consistent.  Out of respect for the recipient, I've not followed up with hushmail technical support.