CryptoFilter · The S/MIME Gateway

CryptoFilter is a pass-through S/MIME gateway for Microsoft Exchange

Works with:

Any version of Microsoft Exchange server including Small Business Server and Office 365
Any SMTP server like IMail, Lotus Notes and Novell GroupWise

S/MIME:

Decrypts messages to enable spam and virus scanning
Validates the signature and optionally reject messages
Encrypts and signs outgoing messages using a single certificate

Benefits:

Encrypt all messages between two servers using a single certificate
Server based policy handling rather then confused end-users

Optional Features:

Encrypts communication using opportunistic SSL/TLS
TLS validation using DANE (DNS-based Authentication of Named Entities)
Encryption of Exchange TNEF/RTF messages
AES256 message encryption and compression when sending a message to another XWall/CryptoFilter
Acts as a eBilling / eInvoice signature server
Automatically extracts the certificate from incoming messages
Keep a copy of every encrypted message
Runs as a service
Compatible with various Asian, Western and Eastern European languages
Available in English, German, French, Italian, Spanish
How CryptoFilter works

For incoming messages, CryptoFilter needs to get the message before your Exchange server will get it so that it can perform it checks before passing the message over to Exchange. Depending on whether you run CryptoFilter on the same machine as Exchange or on a different machine, CryptoFilter either needs to hook up to port 25 or to act as a relay host (respectively).

For outgoing messages, Exchange server passes the message to CryptoFilter, which performs its checks and then sends the message out in the Internet. From Exchange Servers viewpoint, CryptoFilter is a normal relay host.

So the message flow for incoming messages would be Internet -> CryptoFilter -> Exchange server and for outgoing messages it would be Exchange server -> CryptoFilter -> Internet

System Requirements

Windows 2000/2003/2008/2012/2016

Linux with wine / wine-console

Microsoft Exchange, Lotus Notes or any other SMTP server

Installation

Decide if CryptoFilter should be installed on the Exchange server or on a different machine:

Single Exchange server

If you have only one Exchange server and you have less than 10.000 messages each day, then run CryptoFilter on the Exchange server.

More than one Exchange server in the organization

If you have more than one Exchange server in your organization then you should run CryptoFilter on a different machine or at least at a different ip address, because the Exchange servers communicate internal states using Microsoft propriety SMTP verbs on port 25 and third party gateways like CryptoFilter should not be inserted between internal Exchange servers traffic flow.

Cluster

If you have a cluster then you must run CryptoFilter on a different machine, because CryptoFilter doesn't support a cluster.

Once you decided on which machine you are installing CryptoFilter, perform the following steps:

Run Setup.exe or create a directory on your machine and copy all the files into this directory

Start CryptoFilter Admin (MBAdmin.exe) to configure CryptoFilter

The first time you run CryptoFilter you will be prompted for the following information:

Postmaster's address

The address of the person who is responsible for maintaining CryptoFilter. CryptoFilter will send all error messages to this address.

The name or IP address of the Exchange server

If CryptoFilter is running on the same machine as the Exchange server than you can (and should) use localhost as the name.

The port Exchange listens

If CryptoFilter is running on the same machine as the Exchange server than use port 24, else use port 25.

Screenshot: CryptoFilter on the same machine as Exchange , CryptoFilter on a different machine

The e-mail domain that your Exchange is responsible

CryptoFilter needs to know for which e-mail domain your Exchange is responsible, so that if can forward messages for this domain to your Exchange.

Screenshot: e-mail domain that your Exchange is responsible

Running CryptoFilter on the same machine as Exchange server

Incoming Messages

If you run CryptoFilter on the same machine as the Exchange, then you must tell Exchange to listen on a separate port; i.e. not port 25, because only one application can listen to a specific port at one time and CryptoFilter needs to be the first application that gets SMTP messages.

Exchange 5.x

To do this open the file services, usually located in C:\WINNT\system32\drivers\etc\SERVICES

with Notepad or any other text editor. Locate the line smtp 25/tcp mail and change 25 to the port

of your choice (use 24 if you are not sure which one you should use) and save the file.

Restart the IMS (Internet Mail Service) of the Exchange server to bring the new settings into affect.

Screenshot: Notepad with SERVICES

Exchange 2000/2003

Start System Manager (Exchange Admin) and select Servers->Your Server->Protocol->SMTP->Default SMTP Virtual Server->Properties.

In this dialog select the tab labeled General and then Advanced and here you can set the port on which this virtual server listens.

Screenshot: Exchange port

Also make sure Anonymous access is allowed or else CryptoFilter is not able to connect to Exchange.

In System Manager (Exchange Admin) select Servers->Your Server->Protocol->SMTP->Default SMTP Virtual Server->Properties. In this dialog select the tab labeled Access and then Authentication and enable Anonymous access.

Screenshot: Exchange access

Restart the SMTP service of Exchange to bring the new setting into effect.

Exchange 2007/2010 and SBS 2008/2011

Start Exchange Management Console and select Server Configuration->Hub Transport->Receive Connectors

Exchange 2007/2010 has two receive connectors, Client SRV and Default SRV.

SBS 2008 has three receive connectors, Client SRV and Default SRV and Windows SBS Fax SharePoint Receive SRV.

SBS 2011 has two receive connectors, Default SRV and Windows SBS Fax SharePoint Receive SRV.

Default SRV and Windows SBS Fax SharePoint Receive SRV are the connectors that are bound to port 25 and you either need to change them to port 24 or disable them and create a new connector.

In the first case select the properties of the Default SRV connector and in this dialog select the tab labeled Network and set the port to 24.

In the second case create a new receive connector, type Internet and bind it to port 24.

Screenshot: Exchange 2007/2010 inbound connector list, Exchange 2007/2010 port

On Exchange 2007/2010/2013/2016 you need to enable Anonymous user access on the Hub or CryptoFilter can't send to Exchange.

Start Exchange Management Console and select Server Configuration->Hub Transport->Receive Connectors ->Default Connector->Permission Groups and enable Anonymous users.

Or you tell CryptoFilter an user and password so that it can perform a SMTP authentication. Start MBAdmin, select Options->General->Exchange->Exchange needs authentication and type in the user and password.

Note: The user that you use for authentication MUST NOT have a mailbox and MUST be an administrator. DO NOT use Administrator, because there is a mailbox associated with that account and therefore it can't be uses for SMTP authentication.

Note: On Windows 2008/2012/2016 and SBS 2008 you need to open port 25 on the firewall. The firewall has only exceptions for Exchange, but not for CryptoFilter. So unless you open port 25, no mail will come in.

Exchange 2013/2016

Start Exchange Admin Center and select Mail Flow->Receive Connectors

Exchange 2013/2016 has five receive connectors, Client Frontend and Client Proxy and Default and Default Frontend and Outbound Proxy Frontend

Default Frontend is the connectors that are bound to port 25 and you either need to change them to port 24 or disable them and create a new connector.

In the first case select the properties of the Default Frontend connector and in this dialog select the tab labeled Network Adapter Bindings and set the port to 24.

In the second case create a new receive connector, type Internet and bind it to port 24.

Screenshot: Exchange 2013/2016 inbound connector list, Exchange 2013/2016 port

Start Exchange Admin Center and select Mail Flow->Receive Connectors->Default Connector->Security and enable Anonymous users.

Or you tell CryptoFilter an user and password so that it can perform a SMTP authentication. Start MBAdmin, select Options->General->Exchange->Exchange needs authentication and type in the user and password.

Note: The user that you use for authentication MUST NOT have a mailbox and MUST be an administrator. DO NOT use Administrator, because there is a mailbox associated with that account and therefore it can't be uses for SMTP authentication.

Note: On Windows 2008/2012/2016 you need to open port 25 on the firewall. The firewall has only exceptions for Exchange, but not for CryptoFilter. So unless you open port 25, no mail will come in.

Then start MBAdmin, select Options->General->Exchange->Exchange listens on port and type in the same port that you used in Exchange ( e.g. 24).

Outgoing Messages
(this step is optional)

Exchange 5.x

Start Exchange Administrator, select the IMS (Internet Mail Service) and click on the tab labeled Connections.

Enable Forward all messages to host and type in localhost. Close the dialog and restart the IMS.

From then on the Exchange server will forward all messages to the localhost, which basically means it sends them to CryptoFilter.

Exchange 2000/2003

If you have no SMTP connector then start System Manager (Exchange Admin) and select Servers->Your Server->Protocol->SMTP->Default SMTP Virtual Server->Properties.

In this dialog select the tab labeled Delivery and then Advanced and in Smart host type in localhost.

Screenshot: Exchange forward

Close the dialog and restart the SMTP service of Exchange. From then on the Exchange server will forward all messages to the localhost, which basically means it sends them to CryptoFilter.

If you have a SMTP connector then start System Manager (Exchange Admin) and select Routing Groups->Exchange->Connectors->Your SMTP Connector->Properties->Forward all mail through this connector to the following smart host and type in the name or IP address of the machine where CryptoFilter is running.

Close the dialog and restart Exchange. From then on the Exchange server will forward all messages to the name or IP address, which basically means it sends them to CryptoFilter.

Exchange 2007/2010 and SBS 2008/2011

Start Exchange Management Console and select Organization Configuration->Hub Transport->Send Connectors

If there is no connector in the list, then create one, else select the properties of the correct outbound connector.

In this dialog select the labeled Network and then select Route all mail though the following smart host. Press the Add button and add localhost as the smart host.

Screenshot: Exchange 2007/2010 outbound connector list, Exchange 2007/2010 smart host

Close the dialog and restart Exchange. From then on the Exchange server will forward all messages to the name or IP address , which basically means it sends them to CryptoFilter.

Exchange 2013/2016

Start Exchange Admin Center and select Mail Flow->Send Connectors

If there is no connector in the list, then create one, else select the properties of the correct outbound connector.

In this dialog select the labeled Delivery and then select Route mail through smart hosts. Press the Add button and add localhost as the list.

Screenshot:Exchange 2013/2016 outbound connector list, Exchange 2013/2016 smart host

Close the dialog and restart Exchange. From then on the Exchange server will forward all messages to the name or IP address , which basically means it sends them to CryptoFilter.

Running CryptoFilter on a different machine than the Exchange server

Incoming Messages

Start MBAdmin, select Options->General->Exchange->Name or IP address of the Exchange server and type in the name or IP address of the Exchange server.

Screenshot: CryptoFilter on a different machine

Depending on your DNS configuration you will need to change the MX record so that it points to the machine where CryptoFilter is running or else CryptoFilter will not get the messages before Exchange.

Note: On Windows 2003/2008/2012/2016 you need to open port 25 on the firewall. So unless you open port 25, no mail will come in.

Outgoing Messages
(this step is optional)

Exchange 5.x

Start Exchange Administrator, select the IMS (Internet Mail Service) and click on the tab labeled Connections.

Enable Forward all messages to host and type in the name or IP address of the machine where CryptoFilter is running. Close the dialog and restart the IMS. From then on the Exchange server will forward all messages to CryptoFilter.

Exchange 2000/2003

If you have no SMTP connector start System Manager (Exchange Admin) and select Servers->Your Server->Protocol->SMTP->Default SMTP Virtual Server->Properties. In this dialog select the tab labeled Delivery and then Advanced.

In Smart host type in the name or IP address of the machine where CryptoFilter is running.

Close the dialog and restart Exchange. From then on the Exchange server will forward all messages to CryptoFilter.

If you have a SMTP connector then start System Manager (Exchange Admin) and select Connectors->Your SMTP Connector->Properties->Forward all mail through this connector to the following smart host and type in the name or IP address of the machine where CryptoFilter is running.

Close the dialog and restart Exchange. From then on the Exchange server will forward all messages to the name or IP address , which basically means it sends them to CryptoFilter.

Exchange 2007/2010 and SBS 2008/2011

Start Exchange Management Console and select Organization Configuration->Hub Transport->Send Connectors

If there is no connector in the list, then create one, else select the properties of the correct outbound connector.

In this dialog select the labeled Network and then select Route all mail though the following smart host. Press the Add button and add type in the name or IP address of the machine where CryptoFilter is running as the smart host.

Screenshot: Exchange 2007/2010 outbound connector list, Exchange 2007/2010 smart host

Close the dialog and restart Exchange. From then on the Exchange server will forward all messages to the name or IP address , which basically means it sends them to CryptoFilter.

Exchange 2013/2016

Start Exchange Admin Center and select Mail Flow->Send Connectors

If there is no connector in the list, then create one, else select the properties of the correct outbound connector.

In this dialog select the labeled Delivery and then select Route mail through smart hosts. Press the Add button and type in the name or IP address of the machine where CryptoFilter is running as the smart host.

Screenshot:Exchange 2013/2016 outbound connector list, Exchange 2013/2016 smart host

Close the dialog and restart Exchange. From then on the Exchange server will forward all messages to the name or IP address , which basically means it sends them to CryptoFilter.

Once you have done this you can start MBServer and check if all messages are properly routed.

Run CryptoFilter as a service

Once you run CryptoFilter as a service, errors will only be visible in the logfile or in the main window of MBAdmin. Consequently, before running it as a service you must first ensure that CryptoFilter is running properly with no errors by launching it in Console Mode (i.e. starting it from an icon).

In general, installing CryptoFilter as a service should be your last task and not your first.

Note: Keep in mind that CryptoFilter needs to reside on a local disk or the service controller will not be able to start it. Also make sure MBAdmin.exe and MBServer.exe are in the same directory.

Install the service using the GUI

Start MBAdmin, select View->Service and here you can install, remove, start and stop the service. By default it is an AutoStart service and any time your computer is started, CryptoFilter will start.

Note:After you have started CryptoFilter as a service, verify that CryptoFilter has no errors. You need to take a look into the logfile to do this or start MBAdmin and in the main window you see the logfile.

Install the service from the command line

Open a DOS box and change to the directory where CryptoFilter is installed (usually C:\POPBeam or C:\Program Files\CryptoFilter)

Installing CryptoFilter as a service

Start MBServer.exe with the argument of install, by typing

MBServer install

at the command prompt and CryptoFilter will create the service. By default it is an AutoStart service and any time your computer is started, CryptoFilter will start. You can start and stop CryptoFilter at any time via Control Panel

Note: After you have started CryptoFilter as a service, verify that CryptoFilter has no errors. You need to take a look into the logfile to do this or start MBAdmin and in the and in the main window you see the logfile.

Removing CryptoFilter as a service

Start MBServer.exe with the argument of remove, by typing

MBServer remove

at the command prompt and CryptoFilter will delete the service.

How to Stop CryptoFilter

CryptoFilter runs as a console application

Press ESCAPE

Select Close from the system menu

Press Alt-F4

CryptoFilter runs as a service

Open Control Panel, select Services, locate CryptoFilter and press the button labeled Stop

Type

net stop CryptoFilter

at the command prompt

Upgrade to the latest Version

You will find the latest version of CryptoFilter in the Download Center

setup_cryptofilter_??.exe searches for a previously installed CryptoFilter and updates only the executable files. The settings, which are stored in cryptofilter.ini and *.dat, are not touched.

If the CryptoFilter service is running, it is stopped and restarted after the update. In the unlikely event that a executable is locked, the setup program asks for a reboot to change the file. If you refuse the reboot, you need to manually reboot later to bring the new executable into affect.

Note: If you are upgrading from a very old version then you must reapply your registration number.

Helper Programs

Signal is a command line program that allows you to perform the same commands as from the Signal menu of MBAdmin. You can force sending of outbound messages by simply clicking on a link rather than starting MBAdmin.

LogView allows you to view the logfile in real time from any machine on your network. This is especially useful if MBServer runs as a service.

TestMX is a command line program to resolve the MX record for a give domain and then connect to the mail server. The main purpose is to troubleshoot MX related problems or to check if a domain can accept messages.

CSVToEnv is a command line program to recreate the envelope from the statistic file. CSVToEnv is needed to resend messages from the history folder.

TLS/SSL Toolkit contains a generic certificate that you may use for a quick start. Download TLS/SSL Toolkit and extract tlscert.pem and cacert.pem into the XWall directory and then turn on TLS/SSL.

SerializeLog by Softec Integrations AG is a command line program to serialize the XWall logfile to facilitate troubleshooting.

UniqueLog extracts the part from a logfile that belong to an unique id

Licensing Agreement

CryptoFilter ® is copyrighted 1993-2015 by DataEnter GmbH

This product and its documentation may not, in whole or in part, be copied, rent, leased, loaned, resold, assigned, sublicensed, modified, reproduced, transmitted, transcribed, stored in a retrieval system, or translated into any other natural or computer language, in any form or by any means whatsoever, be it electronic, mechanical, magnetic, optical, manual or otherwise, without the prior written consent of DataEnter.

DataEnter makes no warranty or representation, either expressed or implied, with respect to the product CryptoFilter and its documentation, their quality, performance, merchantability, or fitness for a particular purpose. DataEnter reserves the right to revise the user's guide and make changes to the content without obligation to notify any person or organization of such change. In no event will DataEnter be liable for any direct, indirect, special, incidental or consequential damages, real or imagined, resulting from the use or purchase of this software. Under no circumstances shall DataEnter's liability for damages exceed the price paid for the software license. Should any remedy hereunder be determined to have failed, all limitations of liability and exclusion of damages set forth above shall remain in full force and effect. The extent of the DataEnter's warranty for the software and its documentation is limited to physical defects of the distribution media containing the software. Contact DataEnter to obtain return authorization for the replacement diskette within 30 days of the original date of purchase. Any further statement made by agents, employees, distributors or dealers of DataEnter do not constitute warranties and are not binding. No employee of DataEnter has the authority to modify any portion of this warranty.

All brand and product names we refer to in the documentation are used solely for identification purposes and may be trademarks of other companies.

CryptoFilter Standard Edition: DataEnter, (the licensor) grants the buyer (the licensee) the right to use this copy of CryptoFilter Standard Edition (the program) on a single computer at a single location running a single instance and servicing a single Exchange server as long as the licensee complies with the terms of this license.

CryptoFilter Enterprise Edition: DataEnter, (the licensor) grants the buyer (the licensee) the right to use this copy of CryptoFilter Enterprise Edition (the program) on a single computer at a single location running a single instance as long as the licensee complies with the terms of this license.

The licensor reserves the right to terminate this license if the licensee violates any part of the agreement. The licensee agrees to make copies of the program only for backup purposes. The licensee agrees not to copy the documentation and to take all necessary precautions to ensure that the backup copies of the software are not distributed to or acquired by other parties.

Support: Basic support by e-mail is free of charge

Upgrades, Updates: Updates are free, as long as the major version number does not change. (at present the major version number is v3.x)

 
History

v3.09 2017-02-27

  • New: Limit inbound concurrent connection from a single host (InboundSMTPConcurrentConnections=100)
  • New: AES256 encryption and compression when sending a message to another CryptoFilter/XWall (InboundESMTPXBDATAAESA=True,OutboundESMTPXBDATAAESA=True)
  • New: Adaptation for Windows 2016 and Windows 10
  • New: Support for RFC 2231 long filename
  • New: Inbound and Outbound exclude from history (KeepMessageFileInboundExclToAddress=@domain.com,KeepMessageFileOutboundExclFromAddress=@domain.com)
  • New: Support for private Enhanced Status Codes in Exchange 2013 and Office 365
  • Chg: DiskFullAlert unit from bytes to megabyte to prevent overflow (check value at View->Advanced Configuration->Advanced)
  • Chg: CPS are converted to Kibit/s or Mibit/s
  • Chg: Queue messages when Exchange returns a temporary Error
  • Chg: Messages for the DSN From: E-Mail address are no longer accepted when relaying is disabled
  • Chg: Windows NT 4.0 is no longer supported
  • Chg: Exe signed with SHA256, signature only valid on Windows 2008 R2 and above
  • Chg: SSLv2 and SSLv3 is no longer supported
  • Chg: RC4-MD5 and RC4-SHA is no longer supported for inbound connections
  • Chg: SMIME RFC 5751 (micalg=sha1 to micalg=sha-256)
  • Chg: Support for application/pdf Media Type (RCC 3778)
  • Chg: Support for Office 2007 File Format MIME Types
  • Chg: OpenSSL updated to v1.1.0e
  • Del: RAS, ETRN and SOCKS
  • Fix: Len of password for SMTP authentication with Amazon SES
  • Fix: SMIME with an e-mail address that starts with a reserved filename
  • Fix: MBAdmin disable inbound authentication when old settings are still in place
  • Fix: MBAdmin wrote INI in wrong directory after a common dialog changed the current directory
  • Fix: INI entry with a semicolon in a quoted string
  • Fix: DNS MX query missed EDNS0 option
  • Fix: MIME coding for filename with an Umlaut and an ASCII body text
  • Fix: DKIM signing for non-delivery-message
  • Fix: SMIME quote e-mail with a leading space
 
 
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support@dataenter.co.at
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