I followed the Perfect Server for ISPConfig3 using CentOS, NGINX, and I can send from my Squirrelmail, but I cannot receive. I get the following error: Recipient address rejected: undeliverable address: User unknown The email address you entered couldn't be found. Please check the recipient's email address and try to resend the message. If the problem continues, please contact your helpdesk.
Did you create the email domain and email mailbox in ispconfig? If yes, then please check the mail.log for errors.
