Email not being sent with correct configuration?

Question

symfony

I test smtp via https://www.smtper.net/
the letter comes
, I add it to my application

RCPT TO:
<< 554 5.7.1 : Recipient address rejected: Access denied
!! Expected response code 250/251/252 but got code "554", with message "554 5.7.1 : Recipient address rejected: Access denied
" (code: 554)
>> RSET

in the code I send via Swift. the code is correct maybe with a different configuration everything works
what can be?
already broke my head checking everything