<div>
You must to design mail routing during your coexistence period.<br />
<br />
Assuming you will use your old server to outgoing-incoming email, you must to create an external connector to receive email from internet: <a href="https://technet.microsoft.com/en-us/library/jj657447(v=exchg.150).aspx" rel="ugc">https://technet.microsoft.com/en-us/library/jj657447(v=exchg.150).aspx</a><br />
<br />
I suggest you prepare your secondary server to receive-send emails from-to internet, then move all mailboxes and finally switch over mailflow from-to internet.
</div>


You must to design mail routing during your coexistence period.

Assuming you will use your old server to outgoing-incoming email, you must to create an external connector to receive email from internet: https://technet.microsoft.com/en-us/library/jj657447(v=exchg.150).aspx [https://technet.microsoft.com/en-us/library/jj657447(v=exchg.150).aspx]

I suggest you prepare your secondary server to receive-send emails from-to internet, then move all mailboxes and finally switch over mailflow from-to internet.

<div>
<div class="content wysiwyg-content">
Scenario: &nbsp;I have existing Exchange 2013 server that has issues with database corruption and it won't update. I have installed a 2nd Exchange 2013 server and service packed etc and with new databases. &nbsp;I have migrated a test mailbox to the new server and can send mail out without a problem. &nbsp;However I cannot receive mail from the internet or from users on the old server. &nbsp;My intention is to decommission the old server, no NLB or DAG required. &nbsp;Sure i'm missing something obvious, just not sure what.<br />
<br />
Additional info. &nbsp;If I look in the queues I have an entry for 'unreachable domain' and error message on a message in that queue; &quot;There is currently no route to the mailbox database.;2;EXH02DB01;0&quot;
</div>
</div>


Scenario:  I have existing Exchange 2013 server that has issues with database corruption and it won't update. I have installed a 2nd Exchange 2013 server and service packed etc and with new databases.  I have migrated a test mailbox to the new server and can send mail out without a problem.  However I cannot receive mail from the internet or from users on the old server.  My intention is to decommission the old server, no NLB or DAG required.  Sure i'm missing something obvious, just not sure what.

Additional info.  If I look in the queues I have an entry for 'unreachable domain' and error message on a message in that queue; "There is currently no route to the mailbox database.;2;EXH02DB01;0"

Moving to new Exchange 2013 server

Exchange is the server side of a collaborative application product that is part of the Microsoft Server infrastructure. Exchange's major features include email, calendaring, contacts and tasks, support for mobile and web-based access to information, and support for data storage.

Exchange

A server is a computer program or a machine that waits for requests from other machines or software (clients) and responds to them. This architecture is called the client–server model. The clients may run on the same computer or may connect to the server over a network. The purpose of a server is to share data or hardware and software resources among clients. Typical computing servers are database servers, file servers, mail servers, print servers, web servers, game servers, and application servers.