I can't receive any emails, sending emails works fine

[Smurfin]

Hi,

I have a problem with my email. Sending mails is working fine, but I can't receive any emails on the accounts I have set up for my domain.

When I send an email from an account ouside my domain to an account in my domain, I get the following error:

A message that you sent could not be delivered to one or more of its
recipients. This is a permanent error. The following address(es) failed:

smurfin@xxxx.xxx
SMTP error from remote mail server after RCPT TO:<smurfin@xxxx.xxx>:
host mail.existhost.com [xxx.xx.xx.xx]: 550 sorry, no mailbox here by that name (#5.1.1)

Receiving mail from an another account within the domain is working fine.

What can I do to correct this problem?
I am a noob at this, the person who configured the server cannot be reached anymore, so I am on my own now

Thanks.

[Lyttek]

Did this domain exist on another server previously? It sounds like a possible DNS issue, where outside computers are still talking to the old server.

[Smurfin]

Yes, this domain was transferred from another server (with a shared IP) to a dedicated server.