Inbound POP messages Bounced back

I have windows SBS 2003 Premium, and it serves the following: DC, DNS, DHCP, Exchange 2003, and ISA 2004.
I need to reinstall IIS, which makes me reinstall Exchange too and remounted the mailbox. We can send mails out and we receive  locally (within the domain) but not from external. If you try to send me a mail on exchange, I will be not receive it and you will get the message below:

"This message was created automatically by mail delivery software.

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:

  mspop3connector.info@mydomain.biz
    SMTP error from remote mailer after RCPT TO:<mspop3connector.info@mydomain.biz>:
    host mx00.1and1.co.uk [212.227.15.186]: 550 <mspop3connector.info@mydomain.biz>:
    invalid address"

We can't receive mails for two days now on Exchange.
Please, help me on this
bizdataAsked:
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florin_sCommented:
Hi,

This seems to be an mx problem, here is a link that explains how mx works:

http://www.petri.co.il/configure_mx_records_for_incoming_smtp_email_traffic.htm

and this is a link where you can check if you have the proper mx in place for your domain:

http://www.mxtoolbox.com/ - just enter your domain name there and if your ok you should see something like this:

1      d.mx.mail.yahoo.com      68.142.202.247      7200
1      e.mx.mail.yahoo.com      216.39.53.1      7200
.....
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MesthaCommented:
As this is SBS I presume that you have run the Configure Email and Connect tot he Internet wizard correctly without any errors?

I have to disagree that it is an MX error because the POP3 connector is mentioned.

Simon.
0
cmccallCommented:
You can also check to make sure that you have your recipient policy set correctly.  Make sure you external domain is still listed as an accepted domain.
0
bizdataAuthor Commented:
the local domain username and the external email addresses are not of the same convention. I had to uncheck the automatically update email address in Exchange properties and add the external email addresses for each users
0

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