Exchange stops receiving SMTP emails when sending large amount of invoices.

Question

We have an exchange server and a computer with an invoicing program loaded on it. At various times of the month, the invoicing program will go through our database and generate email invoices. The problem comes when we try to send them all at once. (Roughly
800 invoices) Each email is slightly different and each email only has one destination, but if we try to send more than about 50 at a time the exchange server will receive the first roughly 100 (amount varies) and then not receive the rest though the sending
app says all messages were sent. I'm sure the issue lays with exchange because we used a simple free smtp mail server program for testing and it received them all without issue.  Is there a place where you set how many SMTP messages the server will
accept in a single session/connection?  Looking at the queue I can also see that the messages arrive one after another at roughly 2-3 second intervals.  Any help would be greatly appreciated.

Answer 1

I would check Message Throttling on the Exchange server.  Specifically the Set-ReceiveConnector settings for MaxInboundConnectionPercentagePerSource
and MaxInboundConnectionPerSource.
http://technet.microsoft.com/en-us/library/bb232205(v=exchg.150).aspx