How to fix a problem with sending mail through Postfix?

Question

postfix

I have my own server, Postfix, the mail is sent correctly, but the letter does not reach some addresses (which, as I understand it, have more detailed filtering):
said: 553
5.7.1 : Client
host rejected: SPAM_ip (in reply to RCPT TO command )
or like this:
said:
550-static.IP.clients.your-server.de [IP] with 550
HOST - more symbols (, . -) in host name. Typically for spammers
(in reply to RCPT TO command)
or like this:
said: 550-"Error
40.5.1: Direct mail from client hosts does not accepted, use your 550 ISPs
mail server" (in reply to RCPT TO command)
Those. everywhere there is a 550th response. IP was checked on blacklists - it is not listed anywhere. Is it possible to change the name "static..clients.your-server.de" or is there another problem?

Answer 1

Reverse DNS zone registered?