Exchange 2013 stops receiving external email after about 8 hours

Question

Hello,
Just installed 2013 excahnge server 3 days ago. We noticed after the first night that we did not receive any external emails throughout the night.  I could not find anything wrong with receive connectors.  Telnet works internally when this
happens but NO access from public side testing with telnet.  After I reboot the exchange server everything functions just fine and normal for about 8 hours until it happens again.
I dont know what to check or look for at this point.  Very new to exchange 2013.  Any kind of advice would be helpful at this time.
It is not a firewall issue.  Same firewall and set of rules that we use for other/old mail servers.  We only have 1 exchange server that has all roles.
Lead Pusher

Answer 1

OK... Did alot of testing and spent some time with Microsoft's support on the phone.
I believe there is actually two problems going on in this thread.
1. Exchange 2013 Admins that have changed the default receive connectors are experiencing a conflict on the scope settings. Make sure that none of the receive connectors are using the same ports, and that you have not modified the security settings in anyway
unless you really know what you are doing.
If you are unsure of what the settings should be after you have change them, the only suggestion I have right now, (as I have not taken the time to do screen shots or write down all the default settings) is to install Exchange 2013 on a virtual machine and
look at them, then change back the settings that do not match.
2. The Malware Agent has a flaw that is causing the the Microsoft Exchange Transport service to endlessly wait on the Malware Agent to process a message that it just can't handle. (Two reboots of the entire server may be needed to clear this, or sometimes
you can get away with restarting the Microsoft Exchange EdgeSync service.)
The Microsoft technician had me perform a sequence of steps that highlighted this. To see if this is infact your problem you can perform the following steps.
A)  Once the Exchange server stops processing messages, figure out the rough time it stopped processing messages.
B)  Open the event viewer.
C)  Under "Windows Logs", right click "Application", select "Filter Current Log...", check "Warning" and "Error", then click "OK".
D) Scroll down the log to the rough time that your Exchange Server stopped processing messages. You are looking for a slew of errors about the same time from "MSExchange Extensibility" (1051), "MSExchange Transport" (9201), "MSExchange
Transport" (9201), "MSExchange Extensibility" (1056), "MSExchangeTransport" (10003), and "MSExchange Common" (4999).
It is the "MSExchangeTransport" (10003) that I believe is the real problem. The Microsoft technician agreed. He did not want to spectulate as to exactly what was going on, but it seems to me that since he had me disable the "Malware Agent"
for now, that it is indeed the problem. 
E) So.... Open the Exchange Management Console and type "Disable-TransportAgent", followed by enter. It will prompt "Supply values for the following parameters:". Enter "Malware Agent", press enter again. Type "A",
for yes to all.
or
http://technet.microsoft.com/en-us/library/jj150526.aspx"
F) Go to run, enter "services.msc". On the window that opens, find "Micorosoft Exchange Transport" and restart it.
I know this is NOT a fix, but a work around that is less than desired as the Malware Agent is a filter to keep unwanted emails out. I highly recommend running some sort of 3rd party spam/Malware filter that has been fully tested to run with Exchange
2013 if you do this.
Microsoft is to contact me back once they can figure out why this is happening, and I believe in the end a patch for Exchange 2013 will be produce to correct the problem.
In the mean time.... don't waste your money on paying Micorosoft for support, as I have already done this.
For the individuals who say they are not experiencing trouble, I am going to go out on a limb here and say that either you have a 3rd party software program that is filtering the mail before it reaches the Malware Agent, you have disabled the Malware Agent,
or you are using another mail server to forward email to your Exchange 2013 server. With either of these cases you are much less likely to see this problem.
One last issue that a few people may be experiencing, is Exchange 2013, running on Server 2012 that is a VM. Several VM setups have a bug with the VM NIC management interface and Windows Server if you are using the same NIC for both. For example Xen
Server 5.6 and XEN XCP both have this bug. There is an patch for XEN Server 5.6, but so far nothing for Xen XCP.
I have spent many hours trying to figure my problems with Exchange 2013 and I will not swear that my entire post is correct, but I have gotten very much closer to a stable mail server after much work. If you feel that anything is incorrect, please reply
back and let me know why, so that we may all benifit.
P.S. Sorry for the mis-spellings and what not, I am very tired at the moment, and was forced to use explorer, because this site is not liking Chrome at the moment. (Will not let me login)