Hi, could you point me right direction in my problem? I have domain poliman.net on one server. In this domain dns zone I have created A record matching s1 with ip of another server. This "another server" has few domains and mail domains. Each of them has own dns zone and own mailserver, i.e. mail.derm-in.pl, mail.lcprinting.eu. I would like to configure s1.poliman.net as the MX for all of these domains. I suppose that I should only change MX record for each domain. Am I right? But there is a problem with s1.poliman.net as mail domain. I have [email protected] mailbox with s1.poliman.net as pop3/imap and smtp servers but I can only send emails from this mailbox, I can't receive - user who send email on this mailbox get bounced with information that this mailbox doesn't exists - here is the screen https://nofile.io/f/nKJhTrctwGb/fail+delivery.png. It looks like disabling receiving in ISP but it doesn't. I attach link to screen - https://nofile.io/f/Gupc45qP7cg/mailbox+settings.png. In poliman.net dns zone is mail.poliman.net MX record but if I would configure it instead of s1.poliman.net as pop3/imap/smtp for [email protected] mailbox then I can't receive and send emails, so it's not right mailserver, which is obvious.