Everytime I make a new thread about airdrop why disapear?
You're not providing enough details about what threads you created, what exactly the content of those posts were, and which section(s) you posted them in. How do you expect anyone to give you answers if you're just making a vague complaint?
I make the thread at a right topic place.
And what "right topic place" would that be? I'm not even sure where discussions about airdrops go these days, but I'm assuming they're appropriate for one of the altcoin boards. And as Mbitr alluded to, if you included a referral link in any of your posts, that's grounds for deletion since it's against the rules.
If any post deleted, there are should a notification through message coming to inbox it is not?
If a post was deleted by a moderator and not the creator of a self-moderated thread then yes, you should have gotten a PM telling you that your post was deleted. If you didn't, it's possible that a post you quoted got nuked, which would nuke yours as well (I'm pretty sure about that). Did you have a whole thread (or multiple) get deleted? If that's the case, I'm not sure if you get a PM about that or not. It could have been considered spammy depending on what was written. Do you happen to have a quote or something?