Hmm, this is an interesting and complicated case. Trying to decide how I feel about it
First of all, services like Touchnote are allowed by Postcrossing, and although I’m not a fan of them, I do accept the rules. We don’t get to choose what cards we receive or how they’re sent, and it’s up to the sender if they want to use a (professional) third-party service.
This case seems different to me because it wasn’t a professional service, and I’m not sure if it’s technically allowed or not.
I guess I would think nothing of it if a blind person or someone who couldn’t use their hands dictated a message to a friend or family member, or a bedridden person wrote cards and then had a caretaker drop them in the mailbox, et cetera. That would fall under using the address “for Postcrossing purposes” because for them, help from another person is a necessary step in sending the card.
It’s very different than sharing an address in the sense of adding someone to a mailing list, posting their info online, or even a well-meaning “They have so much in common with my friend so-and-so, who’s looking for penpals, I’ll give her their address.” which I believe is what’s meant by not sharing addresses, not some draconian rule against having help mailing the card
I guess to me, it comes down to how necessary the help was, which we really have no way of knowing. If mail from the sender’s country is so horribly unreliable, or postage so expensive and themselves so poor, that that’s the only way they can participate, then I’d rather have them part of this beautiful community than not - even if that means getting creative with how they send cards.
Still, as the recipient, I would probably feel disappointed if I suspected they could have sent the card themselves, and just didn’t have the patience to wait for cards to travel through a slow-but-reliable postal service.
Maybe the sender is new, and will gain more patience with practice