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POP3/IMAP problem with 2010 mailboxes RRS feed

  • Question

  • I recently migrated from Exchange 2003 to Exchange 2010. We are currently in coexistence mode for a while to allow time for transferring all mailboxes (15 000 +) from 2003 to 2010 servers. The problem is with POP3 / IMAP access with Exchange 2010 mailboxes.

     

    A few facts about my situation:

    - Yes, POP3 and IMAP services are enabled and on automatic startup on the 2010 CA server

    - Users with 2003 mailboxes can POP/ IMAP the 2010 CA server without problems

    - Users with 2010 mailboxes cannot POP/IMAP the 2010 CA server (even a brand-new user created through the EMC with an Exchange 2010 mailbox (never moved from 2003))

    - The POP server on the 2010 CA server is set for plain text login (does not accept NTLM), this is the desired setting because most of my clients are set up that way

    - This is not a protected groups issue

    - This is not a firewall issue

    - The client configuration is ok and has been triple-checked

    - The username and pwd has been triple-checked

    - OWA and Outlook access works without problems (for both types of mailboxes: 2003 and 2010)

     

    Error messages:

    - POP error message on the mail client (Thudnerbird 3): "Sending of password did not succeed. Mail server xxxxxxxxxx responded: Server Unavailable. 21"

    - IMAP error message on the mail client (Thudnerbird 3): "Server xxxx has disconnected. The server may have gone down or there may be a network problem."

    - POP3 log excerpt for a non-working user (mtest02) (raised to expert mode):

    • OpenSession
    • capa
    • auth Plain R="-ERR Logon failure: unknown user name or bad password.";RpcL=-1;LdapL=-1;Msg="User:mtest _. 02:a05d8345-2b88-4b92-a2ca-65d1005b362f:General01:2010mbserver.domain.xxxxxxxx";Excpt="Could not load file or assembly 'Microsoft.Exchange.Compliance, Version=14.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35' or one of its dependencies. The system cannot find the file specified.-FileNotFoundException"
    • user mtest02 R=ok;RpcL=-1;LdapL=-1
    • pass ********* R="-ERR Server Unavailable. 21";RpcL=-1;LdapL=-1;Msg="User:mtest _. 02:a05d8345-2b88-4b92-a2ca-65d1005b362f:General01:SLEXMB01.bureautique.uqar.qc.ca";Excpt="Could not load file or assembly 'Microsoft.Exchange.Compliance, Version=14.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35' or one of its dependencies. The system cannot find the file specified.-FileNotFoundException"
    • CloseSession

    - IMAP log excerpt for a non-working user (mtest02) (raised to expert mode):

    • OpenSession
    • capability     R=ok;RpcL=-1;LdapL=-1
    • authenticate     plain        R="2 NO AUTHENTICATE failed.";RpcL=-1;LdapL=-1;Msg=AuthFailed:LogonDenied
    • login    mtest02  ******   R="4 NO LOGIN failed.";RpcL=-1;LdapL=-1;Msg=LogonFailed:LoginDenied
    • CloseSession

     

    Get-PopSettings  (on the CA 2010 server)  (with actual server names changed)

     

    RunspaceId                        : ba93e94d-ed24-45e8-be0c-cfc82f646c5a
    Name                              : 1
    ProtocolName                      : POP3
    MaxCommandSize                    : 512
    MessageRetrievalSortOrder         : Ascending
    UnencryptedOrTLSBindings          : {:::110, 0.0.0.0:110}
    SSLBindings                       : {:::995, 0.0.0.0:995}
    InternalConnectionSettings        : {caserver.domain.abc:995:SSL, caserver.domain.abc:110:TLS}
    ExternalConnectionSettings        : {}
    X509CertificateName               : CASERVER
    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                   : 110
    CalendarItemRetrievalOption       : iCalendar
    OwaServerUrl                      :
    EnableExactRFC822Size             : False
    LiveIdBasicAuthReplacement        : False
    SuppressReadReceipt               : False
    ProtocolLogEnabled                : True
    EnforceCertificateErrors          : False
    LogFileLocation                   : C:\Program Files\Microsoft\Exchange Server\V14\Logging\Pop3
    LogFileRollOverSettings           : Daily
    LogPerFileSizeQuota               : 0 B (0 bytes)
    ExtendedProtectionPolicy          : None
    EnableGSSAPIAndNTLMAuth           : True
    Server                            : CASERVER
    AdminDisplayName                  :
    ExchangeVersion                   : 0.10 (14.0.100.0)
    DistinguishedName                 : CN=1,CN=POP3,CN=Protocols,CN=CASERVER,CN=Servers,CN=Exchange Administrative Group (
                                        FYDIBOHF23SPDLT),CN=Administrative Groups,CN=XXXX,CN=Microsoft Exchange,CN=Services
                                        ,CN=Configuration,DC=domain,DC=abc
    Identity                          : CASERVER\1
    Guid                              : a25a9582-8486-4dc6-8380-649a56f211f2
    ObjectCategory                    : domain.abc/Configuration/Schema/ms-Exch-Protocol-Cfg-POP-Server
    ObjectClass                       : {top, protocolCfg, protocolCfgPOP, protocolCfgPOPServer}
    WhenChanged                       : 2011-08-22 16:30:11
    WhenCreated                       : 2011-08-18 12:06:17
    WhenChangedUTC                    : 2011-08-22 20:30:11
    WhenCreatedUTC                    : 2011-08-18 16:06:17
    OrganizationId                    :
    OriginatingServer                 : DC.domain.abc
    IsValid                           : True

     

    Get-ImapSettings (on the CA 2010 server) (with actual server names changed)

     

    RunspaceId                        : ba93e94d-ed24-45e8-be0c-cfc82f646c5a
    ProtocolName                      : IMAP4
    Name                              : 1
    MaxCommandSize                    : 10240
    ShowHiddenFoldersEnabled          : False
    UnencryptedOrTLSBindings          : {:::143, 0.0.0.0:143}
    SSLBindings                       : {:::993, 0.0.0.0:993}
    InternalConnectionSettings        : {CASERVER.domain.abc:993:SSL, CASERVER.domain.abc:143:TLS}
    ExternalConnectionSettings        : {}
    X509CertificateName               : CASERVER
    Banner                            : The Microsoft Exchange IMAP4 service is ready.
    LoginType                         : PlainTextLogin
    AuthenticatedConnectionTimeout    : 00:30:00
    PreAuthenticatedConnectionTimeout : 00:01:00
    MaxConnections                    : 2147483647
    MaxConnectionFromSingleIP         : 2147483647
    MaxConnectionsPerUser             : 16
    MessageRetrievalMimeFormat        : BestBodyFormat
    ProxyTargetPort                   : 143
    CalendarItemRetrievalOption       : iCalendar
    OwaServerUrl                      :
    EnableExactRFC822Size             : False
    LiveIdBasicAuthReplacement        : False
    SuppressReadReceipt               : False
    ProtocolLogEnabled                : True
    EnforceCertificateErrors          : False
    LogFileLocation                   : C:\Program Files\Microsoft\Exchange Server\V14\Logging\Imap4
    LogFileRollOverSettings           : Daily
    LogPerFileSizeQuota               : 0 B (0 bytes)
    ExtendedProtectionPolicy          : None
    EnableGSSAPIAndNTLMAuth           : True
    Server                            : CASERVER
    AdminDisplayName                  :
    ExchangeVersion                   : 0.10 (14.0.100.0)
    DistinguishedName                 : CN=1,CN=IMAP4,CN=Protocols,CN=CASERVER,CN=Servers,CN=Exchange Administrative Group
                                        (FYDIBOHF23SPDLT),CN=Administrative Groups,CN=XXXX,CN=Microsoft Exchange,CN=Service
                                        s,CN=Configuration,DC=domain,DC=abc
    Identity                          : CASERVER\1
    Guid                              : c6bb7acf-d305-47b1-b0fa-6b29f054a4f2
    ObjectCategory                    : domain.abc/Configuration/Schema/ms-Exch-Protocol-Cfg-IMAP-Server
    ObjectClass                       : {top, protocolCfg, protocolCfgIMAP, protocolCfgIMAPServer}
    WhenChanged                       : 2011-08-28 21:07:44
    WhenCreated                       : 2011-08-18 12:06:17
    WhenChangedUTC                    : 2011-08-29 01:07:44
    WhenCreatedUTC                    : 2011-08-18 16:06:17
    OrganizationId                    :
    OriginatingServer                 : DC.domain.abc
    IsValid                           : True

     

    That's about it for now.  Any help is appreciated.


    Michel Dubé IT analyst (servers) - UQAR
    Monday, August 29, 2011 7:02 PM

Answers

  • My problem is solved. I opened a support call with Microsoft and it turns out that something was indeed missing from the following files:

    C:\program files\Microsoft\Exchange Server\V14\ClientAccess\PopImap\Microsoft.Exchange.Pop3.exe.config

    C:\program files\Microsoft\Exchange Server\V14\ClientAccess\PopImap\Microsoft.Exchange.Imap4.exe.config

     

    The following lines were supposed to be there and had to be added manually:

    <dependentAssembly>
    <assemblyIdentity name="Microsoft.Exchange.Compliance" publicKeyToken="31bf3856ad364e35" culture="neutral" />
    <codeBase version="14.0.0.0" href="file:///C:\Program Files\Microsoft\Exchange Server\V14\bin\Microsoft.Exchange.Compliance.dll" />
    </dependentAssembly>

    After restarting the POP3 and IMAP service on the CAS, everything worked ok.

    After I asked about what caused the problem, the support rep told me that it was related to a bug with Exchange installations that already include SP1. It also seems that my situation was not a common case.

     


    Michel Dubé IT analyst (servers) - UQAR

    • Marked as answer by TheShape1 Friday, September 2, 2011 1:48 AM
    • Edited by TheShape1 Friday, September 2, 2011 1:50 AM
    Friday, September 2, 2011 1:48 AM

All replies

  • Hi,

    Please try to use Outlook Express to test the issue first. We need to verify if it is a Thunderbird client related issue.

    Please try to remove TSL from Internalconnectionsettings and then check the issue again.

    Please enable protocol logging for POP3 and IMAP4 on Exchange Server. Try to post the log here.

    Also you can check event log on Exchange Servers.

    Besides, I recommend you to apply the latest update for your Exchange Server.

     

    Xiu

    Tuesday, August 30, 2011 7:22 AM
  • The POP3 service crashes when a user connects to a mailbox that is migrated from an Exchange Server 2003 server to an Exchange Server 2010 server through the POP3 protocol

    http://support.microsoft.com/?kbid=979431

    Tuesday, August 30, 2011 7:25 AM
  •  Hi,

    Thanks for the info.  Here are my replies to your suggestions.

     

     "Please try to use Outlook Express to test the issue first. We need to verify if it is a Thunderbird client related issue."

    This is not a client related issue.  I tried to connect to the POP3 server using Telnet with the same error "-ERR Server Unavailable. 21"   

     

    "Please try to remove TSL from Internalconnectionsettings and then check the issue again."

    How do I do that?  The POP and IMAP are already setup without TLS in EMC:

    With the set-popsettings cmdlet, the Microsoft Exchange 2010 SP1 says that it's either TLS or SSL for the InternalConnectionSettings parameter: 

    http://technet.microsoft.com/en-us/library/aa998252.aspx

    "Enter a value using the format: <HostName>:<Port>: <Encryption Type>. The <Encryption Type> part of the multivalued value is optional. Valid values for <Encryption Type> are either TLS or SSL."

    Or is there something I don't understand?

     

    "Please enable protocol logging for POP3 and IMAP4 on Exchange Server. Try to post the log here."

    It's in my original post...  Here is it again:

    POP3 log excerpt for a non-working user (mtest02) (raised to expert mode):

    • OpenSession
    • capa
    • auth Plain R="-ERR Logon failure: unknown user name or bad password.";RpcL=-1;LdapL=-1;Msg="User:mtest _. 02:a05d8345-2b88-4b92-a2ca-65d1005b362f:General01:2010mbserver.domain.xxxxxxxx";Excpt="Could not load file or assembly 'Microsoft.Exchange.Compliance, Version=14.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35' or one of its dependencies. The system cannot find the file specified.-FileNotFoundException"
    • user mtest02 R=ok;RpcL=-1;LdapL=-1
    • pass ********* R="-ERR Server Unavailable. 21";RpcL=-1;LdapL=-1;Msg="User:mtest _. 02:a05d8345-2b88-4b92-a2ca-65d1005b362f:General01:SLEXMB01.bureautique.uqar.qc.ca";Excpt="Could not load file or assembly 'Microsoft.Exchange.Compliance, Version=14.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35' or one of its dependencies. The system cannot find the file specified.-FileNotFoundException"
    • CloseSession

    - IMAP log excerpt for a non-working user (mtest02) (raised to expert mode):

    • OpenSession
    • capability R=ok;RpcL=-1;LdapL=-1
    • authenticate plain R="2 NO AUTHENTICATE failed.";RpcL=-1;LdapL=-1;Msg=AuthFailed:LogonDenied
    • login mtest02 ****** R="4 NO LOGIN failed.";RpcL=-1;LdapL=-1;Msg=LogonFailed:LoginDenied
    • CloseSession

     

     or do you mean another type of log?

     

    "Besides, I recommend you to apply the latest update for your Exchange Server."

    Exchange 2010 SP1 UR4.  Sorry I didn't mention this in my original post.

     

    "Also you can check event log on Exchange Servers."

    No issues, warning or errors related to POP3 in the CA server application log.  In the security log, I found 3 logon/logff information events related to the same accounts used for the previous examples in my original post.  It seems to indicate that the logon attempt was a success.  Something wrong seems to be happening after the user logs on to the POP server.

    Included here are the 3 events:

    EVENT ID 4648:

    Log Name:      Security
    Source:        Microsoft-Windows-Security-Auditing
    Date:          2011-08-30 10:06:51
    Event ID:      4648
    Task Category: Logon
    Level:         Information
    Keywords:      Audit Success
    User:          N/A
    Computer:      CASERVER.domain.abc
    Description:
    A logon was attempted using explicit credentials.

    Subject:
     Security ID:  NETWORK SERVICE
     Account Name:  CASERVER$
     Account Domain:  DOMAIN
     Logon ID:  0x3e4
     Logon GUID:  {00000000-0000-0000-0000-000000000000}

    Account Whose Credentials Were Used:
     Account Name:  mtest02
     Account Domain:  DOMAIN
     Logon GUID:  {00000000-0000-0000-0000-000000000000}

    Target Server:
     Target Server Name: localhost
     Additional Information: localhost

    Process Information:
     Process ID:  0x1508
     Process Name:  C:\Program Files\Microsoft\Exchange Server\V14\ClientAccess\PopImap\Microsoft.Exchange.Pop3.exe

    Network Information:
     Network Address: -
     Port:   -

     

    EVENT ID #4624

    Log Name:      Security
    Source:        Microsoft-Windows-Security-Auditing
    Date:          2011-08-30 10:06:51
    Event ID:      4624
    Task Category: Logon
    Level:         Information
    Keywords:      Audit Success
    User:          N/A
    Computer:      SLEXCA01.bureautique.uqar.qc.ca
    Description:
    An account was successfully logged on.

    Subject:
     Security ID:  NETWORK SERVICE
     Account Name:  SLEXCA01$
     Account Domain:  BUREAUTIQUE
     Logon ID:  0x3e4

    Logon Type:   8

    New Logon:
     Security ID:  BUREAUTIQUE\mtest02
     Account Name:  mtest02
     Account Domain:  BUREAUTIQUE
     Logon ID:  0x1a50bafb
     Logon GUID:  {00000000-0000-0000-0000-000000000000}

    Process Information:
     Process ID:  0x1508
     Process Name:  C:\Program Files\Microsoft\Exchange Server\V14\ClientAccess\PopImap\Microsoft.Exchange.Pop3.exe

    Network Information:
     Workstation Name: SLEXCA01
     Source Network Address: -
     Source Port:  -

    Detailed Authentication Information:
     Logon Process:  Advapi 
     Authentication Package: MICROSOFT_AUTHENTICATION_PACKAGE_V1_0
     Transited Services: -
     Package Name (NTLM only): -
     Key Length:  0

     

    EVENT ID #4634

    Log Name:      Security
    Source:        Microsoft-Windows-Security-Auditing
    Date:          2011-08-30 10:06:51
    Event ID:      4634
    Task Category: Logoff
    Level:         Information
    Keywords:      Audit Success
    User:          N/A
    Computer:      SLEXCA01.bureautique.uqar.qc.ca
    Description:
    An account was logged off.

    Subject:
     Security ID:  BUREAUTIQUE\mtest02
     Account Name:  mtest02
     Account Domain:  BUREAUTIQUE
     Logon ID:  0x1a50bafb

    Logon Type:   8

     


    Michel Dubé IT analyst (servers) - UQAR
    Tuesday, August 30, 2011 2:50 PM
  • The POP3 service crashes when a user connects to a mailbox that is migrated from an Exchange Server 2003 server to an Exchange Server 2010 server through the POP3 protocol

    http://support.microsoft.com/?kbid=979431

     

    The Exchange 2010 servers have been installed with SP1 and UR4.  The KB mentions that UR2 solved the problem.

     

    I checked the event logs on the CA server and found no event  #4999 related to POP3 has mentioned in the KB.  I found a few 4999 but only for IMAP.   Here is one example:

    og Name:      Application
    Source:        MSExchange Common
    Date:          2011-08-30 09:38:33
    Event ID:      4999
    Task Category: General
    Level:         Error
    Keywords:      Classic
    User:          N/A
    Computer:      CASERVER.domain.abc
    Description:
    Watson report about to be sent for process id: 1860, with parameters: E12, c-RTL-AMD64, 14.01.0323.003, M.Exchange.Imap4, M.Exchange.Imap4, M.E.I.Imap4ResponseFactory.AuthenticationDone, System.NullReferenceException, 432e, 14.01.0323.003.

     


    Michel Dubé IT analyst (servers) - UQAR

    Tuesday, August 30, 2011 2:52 PM
  • Hi,

    How many CAS servers in the network?

    Please check if we have any space created with accepted domain in the name.

    Please check   to see if Microsoft.Exchange.compliance conifgured in the Microsoft.Exchange.pop3.exe.config file.

     <assemblyIdentity name="Microsoft.Exchange.Compliance" publicKeyToken="31bf3856ad364e35" culture="neutral" />
             <codeBase version="14.0.0.0" href="file:///%ExchangeInstallDir%bin\Microsoft.Exchange.Compliance.dll" />

    Regards,

    Xiu

     

     

    Wednesday, August 31, 2011 3:40 AM
  • Hi,

     Anwsers to your questions and suggestions:

    "How many CAS servers in the network?"

    Currently, we have 4 Exchange 2010 servers (all fresh installs on new hardware and a new install of 2008R2)

    - 1 Client Access

    - 1 Hub Transport

    - 2 Mailbox

     

    Please check if we have any space created with accepted domain in the name.

    I am not sure of what you mean by this. However, I can confirm that the accepted domains are present and working for incoming mail.

     

    "Please check to see if Microsoft.Exchange.compliance conifgured in the Microsoft.Exchange.pop3.exe.config file.

     <assemblyIdentity name="Microsoft.Exchange.Compliance" publicKeyToken="31bf3856ad364e35" culture="neutral" />
     <codeBase version="14.0.0.0" href="file:///%ExchangeInstallDir%bin\Microsoft.Exchange.Compliance.dll" />"

    I've checked the following files and no signs of the word "compliance":

    C:\program files\Microsoft\Exchange Server\V14\ClientAccess\PopImap\Microsoft.Exchange.Pop3.exe.config

    C:\program files\Microsoft\Exchange Server\V14\ClientAccess\PopImap\Microsoft.Exchange.Pop3.exe.config.template

    C:\program files\Microsoft\Exchange Server\V14\ClientAccess\PopImap\Microsoft.Exchange.Pop3.exe.config.template.bak

    C:\program files\Microsoft\Exchange Server\V14\ClientAccess\PopImap\Microsoft.Exchange.Pop3service.exe.config

    C:\program files\Microsoft\Exchange Server\V14\ClientAccess\PopImap\Microsoft.Exchange.Pop3service.exe.config.template

    C:\program files\Microsoft\Exchange Server\V14\ClientAccess\PopImap\Microsoft.Exchange.Pop3service.exe.config.template.bak

     

    I've found the mentioned DLL (Microsoft.Exchange.Compliance.dll) in the following folder:

    C:\program files\Microsoft\Exchange Server\V14\Bin

     

    Thanks again for the feedback


    Michel Dubé IT analyst (servers) - UQAR
    Wednesday, August 31, 2011 6:30 PM
  • My problem is solved. I opened a support call with Microsoft and it turns out that something was indeed missing from the following files:

    C:\program files\Microsoft\Exchange Server\V14\ClientAccess\PopImap\Microsoft.Exchange.Pop3.exe.config

    C:\program files\Microsoft\Exchange Server\V14\ClientAccess\PopImap\Microsoft.Exchange.Imap4.exe.config

     

    The following lines were supposed to be there and had to be added manually:

    <dependentAssembly>
    <assemblyIdentity name="Microsoft.Exchange.Compliance" publicKeyToken="31bf3856ad364e35" culture="neutral" />
    <codeBase version="14.0.0.0" href="file:///C:\Program Files\Microsoft\Exchange Server\V14\bin\Microsoft.Exchange.Compliance.dll" />
    </dependentAssembly>

    After restarting the POP3 and IMAP service on the CAS, everything worked ok.

    After I asked about what caused the problem, the support rep told me that it was related to a bug with Exchange installations that already include SP1. It also seems that my situation was not a common case.

     


    Michel Dubé IT analyst (servers) - UQAR

    • Marked as answer by TheShape1 Friday, September 2, 2011 1:48 AM
    • Edited by TheShape1 Friday, September 2, 2011 1:50 AM
    Friday, September 2, 2011 1:48 AM
  • Thanks for this post. This saved our bacon in the midst of a migration from Exchange 2007 to Exchange 2010 SP1 for 18000+ mailboxes. If this is your problem, you can very easily identify it by enabling POP/IMAP protocol (http://technet.microsoft.com/en-us/library/aa997690.aspx) and look for something similar like the following in the log after you try to connect:

    2011-09-14T13:58:43.941Z,0000000000000018,2,0.0.0.0:993,0.0.0.0:56345,,249,31,30,authenticate,plain,"R=""2 NO AUTHENTICATE failed."";RpcL=-1;LdapL=-1;Msg=""User:<UserLastName, UserFirstName:2fb70c57-89d5-4fc2-bef4-93c06903fbcf:DAG1-DB025:<MailboxServer"";Excpt=""Could not load file or assembly 'Microsoft.Exchange.Compliance, Version=14.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35' or one of its dependencies. The system cannot find the file specified.-FileNotFoundException"""

    Wednesday, September 14, 2011 2:23 PM
  • Thank you as well. We had an issue very similar to this. We just installed Exchange 2010 with sp1 already included. None of the client access server websites would work. In looking at the web.config files we found that the installer did not finish

    In each we replace "%ExchangeInstallDir%" with our exchange directory "C:\Program Files\Microsoft\Exchange Server\V14\" and everything starts working.

    Friday, December 16, 2011 1:56 AM
  • hello every one i have the same case (Theshape1) that the pop3 did not work and the protocol logon indicator that<< R=""-ERR Logon failure: unknown user name or bad password."";Msg=LogonFailed:LoginDenied" >>

    therefore i added the below to this Microsoft.Exchange.pop3.exe.config

    <dependentAssembly>
    <assemblyIdentity name="Microsoft.Exchange.Compliance" publicKeyToken="31bf3856ad364e35" culture="neutral" />
    <codeBase version="14.0.0.0" href="file:///C:\Program Files\Microsoft\Exchange Server\V14\bin\Microsoft.Exchange.Compliance.dll" />
    </dependentAssembly>

    and restart the pop3 service but no luck nothing change!!


    Edward
    Wednesday, January 11, 2012 10:23 AM
  • You seem to have a slightly different problem.  Our initial symptom was not a login denied message but a server unavailable message from the POP and IMAP protocol ("-ERR Server Unavailable. 21").  This led to the solution explained in this thread.  In our case, the logs (windows events and protocol logging) indicated that the login is successful.  The problem occured after authentication. 

    I'm afraid that I don't have many suggestions for you at the moment.  You can try changing the authentication type of the POP protocol in the CA server configuration.  The POP client must also be configured to use an authentication type that is supported by the server.  For example, if the client tries to authenticate securely but the server only accepts basic authentication, this can cause problems.  Begin by setting your POP3 server authentication to plain text logon and setting the client to authenticate the same way.  I would be surprised if it's the problem but it's a quick check.  If it's not the problem, at least you will be able to move to other, more elaborated diagnostics knowing that the basic stuff have been checked.


    Michel Dubé IT analyst (servers) - UQAR
    Wednesday, January 11, 2012 2:10 PM
  • TheShape1 Thank you very much for sharing the issue, i ran into the same issue, when i turned on the IMAP  logging i got the same error as you got

    2012-01-26T18:02:58.889Z,0000000000000001,2,10.185.57.202:143,10.140.77.229:1228,,2262,44,325,authenticate,NTLM,"R=""fcn3 NO AUTHENTICATE failed."";RpcC=17;RpcL=15;LdapC=19;LdapL=32;Msg=User:username:10dc6dfb-ad6b-4b3b-aacf-e6d2445d18b7:MBXDB:MBX.domain.com;Excpt=""Could not load file or assembly 'Microsoft.Exchange.Compliance, Version=14.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35' or one of its dependencies. The system cannot find the file specified.-FileNotFoundException"""
    2012-01-26T18:03:10.636Z,0000000000000002,0,10.185.57.202:993,10.185.68.20:32919,,0,0,0,OpenSession,,
    2012-01-26T18:03:40.604Z,0000000000000003,0,10.185.57.202:993,10.185.68.20:32993,,0,0,0,OpenSession,,
    2012-01-26T18:03:56.094Z,0000000000000001,3,10.185.57.202:143,10.140.77.229:1228,,62,11,59,CloseSession,,"R=""Server Unavailable. 15"";RpcL=-1;LdapL=-1;Msg=AuthFailed:IllegalMessage;Excpt=""Object reference not set to an instance of an object.-NullReferenceException"""
    2012-01-26T18:04:10.603Z,0000000000000004,0,10.185.57.202:993,10.185.68.20:33069,,0,0,0,OpenSession,,
    2012-01-26T18:04:40.617Z,0000000000000005,0,10.185.57.202:993,10.185.68.20:33143,,0,0,0,OpenSession,,

    Thursday, January 26, 2012 10:16 PM
  • Thank you, Michel, that definitely helped! IMAP was working for some accounts but not for all, a strange behavior. I had to enable IMAP logging to be able to find this thread and your brilliant answer :)

    And yes, I did Exchange migration from EX2003 to EX2010 using media with SP1.

    Dusan Zierl, IT Consultant

    Tuesday, March 27, 2012 9:39 AM
  • My problem is solved. I opened a support call with Microsoft and it turns out that something was indeed missing from the following files:

    C:\program files\Microsoft\Exchange Server\V14\ClientAccess\PopImap\Microsoft.Exchange.Pop3.exe.config

    C:\program files\Microsoft\Exchange Server\V14\ClientAccess\PopImap\Microsoft.Exchange.Imap4.exe.config

     

    The following lines were supposed to be there and had to be added manually:

    <dependentAssembly>
    <assemblyIdentity name="Microsoft.Exchange.Compliance" publicKeyToken="31bf3856ad364e35" culture="neutral" />
    <codeBase version="14.0.0.0" href="file:///C:\Program Files\Microsoft\Exchange Server\V14\bin\Microsoft.Exchange.Compliance.dll" />
    </dependentAssembly>

    After restarting the POP3 and IMAP service on the CAS, everything worked ok.

    After I asked about what caused the problem, the support rep told me that it was related to a bug with Exchange installations that already include SP1. It also seems that my situation was not a common case.

     


    Michel Dubé IT analyst (servers) - UQAR


    Saturday, July 21, 2012 4:10 PM