Sorry, it's correct. I have left it solved because, at least temporarily, it allows the output of the mails without the need to eliminate the relay host of the file master.cf, which, in my case, caused problems with other domains of the same VPS.
Hi,
We find the solution here: https://support.plesk.com/hc/en-us/articles/115000063949 [PPM-5259]
Simply, add "-s" string on master.cf at line that begins with plesk_virtual unix
Hi,
We send all mails through spamexperts and they send back with Error. 550 Verification failed. this occurs in one of the domains of this VPS (we can't validate all with same OP in spamexperts panel), deactivating the relay host in main.cf there isn't problem; but we opened a ticket with...