Turns out that thousands of people every year think they are being super clever by putting my email address in the "From" field. So of course I get zillions of "receipts" for these eCards.
"Sister, I hope you feel better soon"
...is the most popular by far.
I stopped looking at them years ago but there's often some very personal information included and if I were an evil supervillain it would be trivial for me to use a lot of these eCards to blackmail people!
Fortunately for these people there's a highly ethical person at the helm of that email address that filters them all right into the trash.