I am helping my church with an issue regarding email.
They host there own email but there site is at a different company.. the problem is that when they send an email to the server there website is hosted on it gets this error
Recipient address rejected: User unknown in virtual mailbox
When the hosting company sends an email to them, they get the same error, the church can send anywhere else in the world and so can the hosting company
Its almost like the hosting companies server (which I have access to) is claiming that they are the authoritative DNS, so when they try to send to the church, since the email is local it looks at the local rule and rejects it, but the servers MX rules go to the church and just the A record goes to the site.... Again, I have access to all parties but have no idea how to fix this :(
P.S. the server uses postfix with Plesk if that helps and the church host their email on an exchange server.