Hello All

I have three servers in an Exchange 2013 DAG.  Lets call them EX2013-MB1, MB2 and MB3.

I have configured POP Across the board.  All of a sudden the other day POP stopped working on MB1.  After some troubleshooting, if I launch a telnet session to port 110 from MB1, it connects and works fine.  Any other machine, nothing, connection immediately drops.

I have the firewall disabled, so it's not the firewall blocking the connection by any means.

Any ideas?  Below are my Get-PopSettings, and Test-PopConnectivity

[PS] C:\Windows\system32>Get-PopSettings | FL


RunspaceId                        : 66d8dee7-2a6e-4fbe-9b20-a15e79da7978
Name                              : 1
ProtocolName                      : POP3
MaxCommandSize                    : 512
MessageRetrievalSortOrder         : Ascending
UnencryptedOrTLSBindings          : {0.0.0.0:110}
SSLBindings                       : {0.0.0.0:995}
InternalConnectionSettings        : {EX2013-MB1.PRIVATE DOMAIN.com:995:SSL, EX2013-MB1.PRIVATE DOMAIN.com:110:TLS}
ExternalConnectionSettings        : {}
X509CertificateName               : EX2013-MB1
Banner                            : The Microsoft Exchange POP3 service is ready.
LoginType                         : PlainTextLogin
AuthenticatedConnectionTimeout    : 00:30:00
PreAuthenticatedConnectionTimeout : 00:01:00
MaxConnections                    : 2147483647
MaxConnectionFromSingleIP         : 2147483647
MaxConnectionsPerUser             : 16
MessageRetrievalMimeFormat        : BestBodyFormat
ProxyTargetPort                   : 9955
CalendarItemRetrievalOption       : iCalendar
OwaServerUrl                      :
EnableExactRFC822Size             : False
LiveIdBasicAuthReplacement        : False
SuppressReadReceipt               : False
ProtocolLogEnabled                : True
EnforceCertificateErrors          : False
LogFileLocation                   : C:\Program Files\Microsoft\Exchange Server\V15\Logging\Pop3
LogFileRollOverSettings           : Daily
LogPerFileSizeQuota               : 0 B (0 bytes)
ExtendedProtectionPolicy          : None
EnableGSSAPIAndNTLMAuth           : True
Server                            : EX2013-MB1
AdminDisplayName                  :
ExchangeVersion                   : 0.10 (14.0.100.0)
DistinguishedName                 : CN=1,CN=POP3,CN=Protocols,CN=EX2013-MB1,CN=Servers,CN=Exchange Administrative
                                    Group (FYDIBOHF23SPDLT),CN=Administrative Groups,CN=FH Paschen,CN=Microsoft
                                    Exchange,CN=Services,CN=Configuration,DC=PRIVATE DOMAIN,DC=com
Identity                          : EX2013-MB1\1
Guid                              : 83942b2a-5dff-4b63-b33b-234944c2bc46
ObjectCategory                    : PRIVATE DOMAIN.com/Configuration/Schema/ms-Exch-Protocol-Cfg-POP-Server
ObjectClass                       : {top, protocolCfg, protocolCfgPOP, protocolCfgPOPServer}
WhenChanged                       : 7/10/2014 3:28:48 PM
WhenCreated                       : 12/24/2013 11:04:05 AM
WhenChangedUTC                    : 7/10/2014 8:28:48 PM
WhenCreatedUTC                    : 12/24/2013 5:04:05 PM
OrganizationId                    :
OriginatingServer                 : FHP-DS8.PRIVATE DOMAIN.com
IsValid                           : True
ObjectState                       : Unchanged

RunspaceId                  : 66d8dee7-2a6e-4fbe-9b20-a15e79da7978
LocalSite                   : MainOffice
SecureAccess                : False
VirtualDirectoryName        :
Url                         :
UrlType                     : Unknown
Port                        : 995
ConnectionType              : Ssl
ClientAccessServerShortName : EX2013-MB1
LocalSiteShortName          : MainOffice
ClientAccessServer          : EX2013-MB1.PRIVATE_DOMAIN.com
Scenario                    : Test POP3 Connectivity
ScenarioDescription         : Connect to server using POP3 protocol, search for the test message, and delete it along
                              with any messages that are older than 24 hours.
PerformanceCounterName      : POPConnectivity-Latency
Result                      : Failure
Error                       : Microsoft.Exchange.Monitoring.ProtocolException: Authentication failed. The connection
                              is being closed.
                              Unable to read data from the transport connection: An established connection was aborted
                              by the software in your host machine.Server response while making connection:[]. --->
                              System.IO.IOException: Unable to read data from the transport connection: An established
                              connection was aborted by the software in your host machine. --->
                              System.Net.Sockets.SocketException: An established connection was aborted by the
                              software in your host machine
UserName                    : extest_08569ee75e264
StartTime                   : 7/10/2014 4:02:33 PM
Latency                     : 00:00:00.0359767
EventType                   : Error
LatencyInMillisecondsString :
Identity                    :
IsValid                     : True
ObjectState                 : New

>>>WhenChanged                       : 7/10/2014 3:28:48 PM
>>>WhenCreated                       : 12/24/2013 11:04:05 AM

Hi,

From the PopSettings information, I found that you recently modified pop3 settings.

Did you try to recover the settings and check if the issue persist?

What's the result if you launch a telnet session to port 110 from other networked machine?

In addition, you should check if the user have the permission to access pop3.

Hope this helps!

Thanks.

Hi,

Any update?

Thanks.

Any updates?  I am having this EXACT same issue!  I have 2 boxes in a DAG, and after a period of time, POP3 decides on my 2nd box that it will no longer accept connections.  Locally on the box, I am able to telnet to port 110 without issue.  Firewall is disabled.

Well, I found the source of my problem, but don't understand why ...

Get-ServerComponentstate -Identity CHIEXC02

Found that the PopProxy Component was inactive, looking in Event logs, found it was bumped to inactive by HealthAPI.

Set-ServerComponentState -Identity CHIEXC02 -Component PopProxy -Requester HealthAPI -State Active

Kicked the component active again, and now POP3 responds from the external IPs.

Having said that, I really want to understand what caused HealthAPI to kick it to Inactive, and why it doesn't kick itself back to active?  Obviously it's a healthcheck that failed.  Now I need to understand WHY.

Well, I found the source of my problem, but don't understand why ...

Get-ServerComponentstate -Identity CHIEXC02

Found that the PopProxy Component was inactive, looking in Event logs, found it was bumped to inactive by HealthAPI.

Set-ServerComponentState -Identity CHIEXC02 -Component PopProxy -Requester HealthAPI -State Active

Kicked the component active again, and now POP3 responds from the external IPs.

Having said that, I really want to understand what caused HealthAPI to kick it to Inactive, and why it doesn't kick itself back to active?  Obviously it's a healthcheck that failed.  Now I need to understand WHY.

• Proposed as answer by Jason SherryMVP Tuesday, August 19, 2014 10:06 PM

Well, I found the source of my problem, but don't understand why ...

Get-ServerComponentstate -Identity CHIEXC02

Found that the PopProxy Component was inactive, looking in Event logs, found it was bumped to inactive by HealthAPI.

Set-ServerComponentState -Identity CHIEXC02 -Component PopProxy -Requester HealthAPI -State Active

Kicked the component active again, and now POP3 responds from the external IPs.

Having said that, I really want to understand what caused HealthAPI to kick it to Inactive, and why it doesn't kick itself back to active?  Obviously it's a healthcheck that failed.  Now I need to understand WHY.

• Proposed as answer by Jason SherryMVP 12 hours 54 minutes ago

Well, I found the source of my problem, but don't understand why ...

Get-ServerComponentstate -Identity CHIEXC02

Found that the PopProxy Component was inactive, looking in Event logs, found it was bumped to inactive by HealthAPI.

Set-ServerComponentState -Identity CHIEXC02 -Component PopProxy -Requester HealthAPI -State Active

Kicked the component active again, and now POP3 responds from the external IPs.

Having said that, I really want to understand what caused HealthAPI to kick it to Inactive, and why it doesn't kick itself back to active?  Obviously it's a healthcheck that failed.  Now I need to understand WHY.

• Proposed as answer by Jason SherryMVP 12 hours 54 minutes ago

Well, I found the source of my problem, but don't understand why ...

Get-ServerComponentstate -Identity CHIEXC02

Found that the PopProxy Component was inactive, looking in Event logs, found it was bumped to inactive by HealthAPI.

Set-ServerComponentState -Identity CHIEXC02 -Component PopProxy -Requester HealthAPI -State Active

Kicked the component active again, and now POP3 responds from the external IPs.

Having said that, I really want to understand what caused HealthAPI to kick it to Inactive, and why it doesn't kick itself back to active?  Obviously it's a healthcheck that failed.  Now I need to understand WHY.

• Proposed as answer by Jason SherryMVP Tuesday, August 19, 2014 10:06 PM

Well, I found the source of my problem, but don't understand why ...

Get-ServerComponentstate -Identity CHIEXC02

Found that the PopProxy Component was inactive, looking in Event logs, found it was bumped to inactive by HealthAPI.

Set-ServerComponentState -Identity CHIEXC02 -Component PopProxy -Requester HealthAPI -State Active

Kicked the component active again, and now POP3 responds from the external IPs.

Having said that, I really want to understand what caused HealthAPI to kick it to Inactive, and why it doesn't kick itself back to active?  Obviously it's a healthcheck that failed.  Now I need to understand WHY.

• Proposed as answer by Jason SherryMVP Tuesday, August 19, 2014 10:06 PM

Just ran into the same issue on a new setup of Exchange 2013. Like you I don't know why this happened, but setting it to Active fixed the issue for me too.

I blogged about it here and hope this helps others find the issue.

http://blog.jasonsherry.net/2014/08/19/exchange-2013-pop3-service-drops-connections-fi

Ran into this same issue but with ImapProxy being Inactive.

Spent hours checking everything but this, so a big thank you for this post.

Scary thing was that I couldn't find any error logs anywhere, let alone any that would've of pointed towards checking the Component State!

Thanks again.

Just wanted to say "I love you" :)

Been busting my head with this for 3 hours now and your post saved my day :)

Thanks for sharing.

I have the same issue but with IMAP4 (993) service.

Get-ServerComponentState -Identitty <name exchange server>

Set-ServerComponentState -Idenntity <name exchange server> -Component ImapProxy -Requestor HealthAPI -Satate Active

resolve p