Looking at comments I’ve seen on Reddit some of the new wave are definitely confused about postage. No one sends letter post these days so it can be hard to know what it costs and you might not even realise there are stamps with different price points.
There’s no harm in mentioning it in your thank you message or you could also report it to support. They won’t do anything unless there’s a concern it’s someone doing it intentionally.
I register such cards with a warm welcome and inform them politely about the postage. Up to now they were thankful for that information.
For anyone who is curious, USA domestic postage for postcards is currently $0.48. International postage, regardless whether it’s a postcard or an envelope, is $1.45. Combinations of postage stamps that add up to that amount are acceptable. For international postage, sometimes I use the $1 commemorative stamp and a $0.48 postcard stamp. I lose three cents but who cares.
As of July 10 those increase to 51¢ domestic and $1.50 international, so that combination becomes more valuable, so to speak.
And the domestic postcard postage rate only applies to postcards up to a certain size. Per the postal explorer:
Anything larger or square/irregularly shaped will require a forever stamp … when in doubt check with your local post office
When I’m doubt, the postage calculator on the USPS website is usually pretty helpful!
I came from OakLeaf’s TikTok as well, but this was at least a couple weeks ago after one of her first videos. I have done a DEEP dive and have embedded myself in the postcrossing and snail mail community. It was something I didn’t know I would love as much as I do. I have a couple postcards that have been registered so far and immediately used up all of the remaining slots. I am also participating in tags and such. I just love the community and I love putting in effort into each postcard I send🤍
I’m afraid to treat them as new, or treat anyone what I think they are 
I once thought someone is child because of their hand writing 
good I didn’t mention it any ways. I think.
I’m also afraid of politely writing anything because apparently I’m not good at it, so I trust the postcrossing team.
(I have sometimes mentioned, maybe they didn’t know, international postage is “amount” and that I understand they maybe accidentally put the postcard stamp. And the answer was so angry, how they have swapped how much longer than me 
totally unrelated things. And someone wrote, “listen you little know-it-all” 
(I wrote her the current values of stamps, so it didn’t seem helpful to her, which I thought).
But if it’s new member, I will mention it with my thank message, if old, postcrossing team knows how to deal with them so I don’t accidentally make them feel like new or not knowing something, if they think it’s bad.
(Someone wrote once to me, how I can send a card with only 0.10€ stamp. That’s the addition, if I use priority mail and use domestic value stamp, so I asked isn’t there another stamp (those don’t show the value, only a little Finland map symbol). They never answered, so I don’t know if I really sent the card with that so underpaid stamp, or they didn’t know the other was a real stamp.)
But I think this is the first time all three cards I get had same style underpayment.
Some people are really ridiculous!
I started writing “welcome” and giving a hint about the postage, for it had turned out before, that all of those users were newbies. Sorry that you had to make such a bad experience!
I didn’t take it bad. But I don’t want to create such reactions in others, if I can choose.
I can understand it can feel strange to get advice from a stranger, who doesn’t live in that country even ( 
). And fun coinsidence, I had then just read, how advice from a woman is often treated as “showing off” and unpolite, while same advice from a man is taken more seriously. Many things to consider in an interplay.
Perhaps should I hide my gender and put a hammer to my avatar 
You’d think people would be nicer in a site like this one. I expect people can have bad days. I know when I received the admonishment for writing my website on one post and the abbreviation for my cards in another (both things I’ve seen other people do all the time) it was at a time when I had just recently lost my best friend and just lost my cat and my emotions were high. I think I flared up a bit about it. The admin who admonished me probably wanted to whip me with a wet noodle. Not an excuse for acting badly but we never know what people are going through. Just kill them with kindness, I guess and try not to take it personally <3
I agree, everyone have bad days, I really didn’t take it bad.
I’m happy there are new members and welcome them of course 
I also like that when Postcrossing has begun, there was no TikTok, so nowadays app find these old hobbies, it’s very cool!
… and change the username to S_Tuulio, for the a at the end makes it look female, at least to me.
To me it seems that even many women take men more seriously than they take other females. 
I forgot to write, I got two more, but one is writing about Thanksgiving.(which can also be like it’s their habit etc, not written at that time).
This is so confusing! Four have very similar hand writing, and message style (like no name, only in one, so it’s like small notes from same person, but how would each have different id), and the underpaid postage in all.
