In a previous post I wrote about my Exchange 2013 CU6 Adventure and how it caused my Exchange Replication Services to crash.
That wasn’t the only issues faced after updating to CU6. It seems that the CU6 upgrade had crippled my ability to use the POP3 service.
I have been waiting for a week now for Microsoft to get back to me regarding a solution. But I was able to find one else ware thanks to Jason (Izzy) Sherry’s Blog Post: Exchange 2013 POP3 service drops connections fix
Symptoms:
- Exchange 2013 POP3 request fail from remote hosts
- Exchange 2013 POP3 request respond from localhost
Troubleshooting Steps:
- Restart POP3 and POP3 Back-end Services
- Reconfigure Exchange POP3 Local IP Address
- Check server for firewall
- Check if 3rd party antivirus may be intercepting POP3 requests
- Inspect traffic using Wireshark
Solution Steps Followed:
In Exchange Powershell type:
Get-ServerComponentstate -Identity SERVERNAME
This will list the Server Component States

Server |
Component |
State |
SERVERNAME |
ServerWideOffline |
Active |
SERVERNAME |
HubTransport |
Active |
SERVERNAME |
FrontendTransport |
Active |
SERVERNAME |
Monitoring |
Active |
SERVERNAME |
RecoveryActionsEnabled |
Active |
SERVERNAME |
AutoDiscoverProxy |
Active |
SERVERNAME |
ActiveSyncProxy |
Active |
SERVERNAME |
EcpProxy |
Active |
SERVERNAME |
EwsProxy |
Active |
SERVERNAME |
ImapProxy |
Active |
SERVERNAME |
OabProxy |
Active |
SERVERNAME |
OwaProxy |
Active |
SERVERNAME |
PopProxy |
Inactive |
SERVERNAME |
PushNotificationsProxy |
Active |
SERVERNAME |
RpsProxy |
Active |
SERVERNAME |
RwsProxy |
Active |
SERVERNAME |
RpcProxy |
Active |
SERVERNAME |
UMCallRouter |
Active |
SERVERNAME |
XropProxy |
Active |
SERVERNAME |
HttpProxyAvailabilityGroup |
Active |
SERVERNAME |
ForwardSyncDaemon |
Active |
SERVERNAME |
ProvisioningRps |
Active |
SERVERNAME |
MapiProxy |
Active |
SERVERNAME |
EdgeTransport |
Active |
SERVERNAME |
HighAvailability |
Active |
SERVERNAME |
SharedCache |
Active |
Now that you have identified the issue; as you can see POPProxy is set to Inactive we need to now set it back to Active
So we issue the following command:
Set-ServerComponentState -Identity SERVERNAME -Component PopProxy -Requester HealthAPI -State Active

As soon as you do this the POP3 Service start to respond again.
Problem now fixed, cause is still unknown. The only thing known in my case is that this occurred after installing Exchange 2013 CU6