How XWall works
For incoming messages, XWall 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 XWall on the same machine as Exchange or on a different machine, XWall 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 XWall, which performs its checks and then sends the message out in the Internet. From Exchange Servers viewpoint, XWall is a normal relay host.
So the message flow for incoming messages would be Internet -> XWall -> Exchange server,
and for outgoing messages it would be Exchange server -> XWall -> Internet
System Requirements
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Windows® NT, Windows® 2000/2003 with TCP/IP installed
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Microsoft Exchange, Lotus Notes or any other SMTP server
Installation
Decide if XWall should be installed on the Exchange server or on a different machine:
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Single Exchange server
If you have only one Exchange server and you have less than 10.000 messages each day,
then run XWall on the Exchange server.
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More than one Exchange server in the organization
If you have more than one Exchange server in your organization then you should run XWall 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 XWALL should not be inserted between internal Exchange servers traffic flow.
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Cluster
If you have a cluster then you must run XWall on a different machine, because XWall doesn't support a cluster.
Once you decided on which machine you are installing XWall, perform the following steps:
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Run Setup.exe or create a directory on your machine and copy all the files into this directory
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Start XWall Admin (MBAdmin.exe) to configure XWall
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The first time you run XWall you will be prompted for the following information:
Postmaster's address
The address of the person who is responsible for maintaining XWall. XWall will send all error messages to this address.
The name or IP address of the Exchange server.
If XWall 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 XWall is running on the same machine as the Exchange server than use port 24, else use port 25.
Screenshot: XWall on the same machine as Exchange , XWall on a different machine
The e-mail domain that your Exchange is responsible
XWall 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
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Running XWall on the same machine as Exchange server
Incoming Messages
If you run XWall 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 XWall needs to be the first application that gets SMTP messages.
Then start MBAdmin, select Options->General->Exchange->Exchange listens on port and type in the same port that you used in Services/System Manager .
Outgoing Messages
(this step is optional and is not needed for inbound spam blocking)
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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 XWall.
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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 XWall.
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 XWall 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 XWall.
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Exchange 2007
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 outbound connector list, Exchange 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 XWall.
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Running XWall 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: XWall 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 XWall is running or else XWall will not get the messages before Exchange.
Outgoing Messages
(this step is optional and is not needed for inbound spam blocking)
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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 XWall is running. Close the dialog and restart the IMS. From then on the Exchange server will forward all messages to XWall.
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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 XWall is running.
Close the dialog and restart Exchange. From then on the Exchange server will forward all messages to XWall.
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 XWall 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 XWall.
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Exchange 2007
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 XWall is running as the smart host.
Screenshot: Exchange outbound connector list, Exchange 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 XWall.
Once you have done this you can start MBServer and check if all messages are properly routed.
Run XWall as a service
Once you run XWall 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 XWall is running properly with no errors by launching it in Console Mode (i.e. starting it from an icon).
In general, installing XWall as a service should be your last task and not your first.
Note: Keep in mind that XWall 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.
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, XWall will start.
Note: After you have started XWall as a service, verify that XWall 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.
For the examples below, we assume XWall is in C:\XWall
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Installing XWall as a service
Start MBServer.exe with the argument of install, by typing MBServer install at the command prompt and XWall will create the service.
By default it is an AutoStart service and any time your computer is started, XWall will start.
You can start and stop XWall at any time via Control Panel
Note: After you have started XWall as a service, verify that XWall 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.
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Removing XWall as a service
Start MBServer.exe with the argument of remove, by typing MBServer remove at the command prompt and XWall will delete the service.
How to stop XWall
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XWall runs as a console application:
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Press ESCAPE
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Select Close from the system menu (works only on Windows NT®)
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Press Alt-F4 (works only on Windows NT®)
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XWall runs as a service on Windows NT®:
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Open Control Panel, select Services, locate
XWall and
press the button labeled Stop
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type Net Stop XWall at the command prompt
Upgrade to the latest Version
You will find the latest version of XWall in the
Download Area Simply stop XWall and then run setup.exe to install the new version.
If you don't stop XWall, the setup program will force a reboot
to bring the new exe into affect.
Note: If you are upgrading from a very old version then you must reapply your registration number.
Tighten Security
To tighten your email security as much as possible enable the following setting:
Fight Spam
There are two ways to fight against spam and both have advantages and disadvantages:
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Block all messages as early as possible
The advantage is that the messages do not reach your server and are blocked as early as possible, most of them at the SMTP protocol level. The drawback is that the administrator needs to handle all the exceptions.
For example, if you enable the Spam Lookup Service (SLS) and you tell XWall to block all messages that are on the spamcop.net list, then this will catch a lot of spam mails ( usually around 50% ).
However, your best customer/supplier/friend/relative will also be blocked because he/she is using a mail server which is on the list. So you need to exclude this mail server and you need to adjust it any time the IP address changes.
What makes the task really time consuming is the fact that the customer/supplier/friend/relative does not simply tell you that your server does not accept mail because it is on a spam list. They will call you and say something like
I can not send to you and you have to figure out what the problem might be.
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Let all messages come in and mark the subject
The advantage of this is that the administrator has absolute no work and it give the most flexibility, because XWall only marks the subject ( it adds a small text like [sls] at the end of the subject ).
The final recipient can then simply setup a rule in his/her email client that deletes all messages where the subject contains [sls]. He/she can maintain a local exception list and do not need to call the administrator for handling an exception. Another option would be to color code the message rather then deleting it.
In practice this this has been proven to be the best way to fight spam.
Note: On Exchange 2003/2007 then you can use Mark subject and move to Junk-E-Mail folder.
However, XWALLFilter , which is an add-on even sink, needs to be installed on your Exchange. For more info on XWALLFilter at click here.
Operations Guide
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Enable Automatic White List - Options->Global Exclude->Exclude - White List
This allows you to use a more aggressive spam catching strategy, because
everyone to whom you send a e-mail is automatically excluded from spam checking,
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Enable Greylisting - Options->Spam->Greylisting
At present by far the best way to block spam, some 80% with nearly no false positive.
Note: make sure the spammer do not bypass Greylisting by sending over your backup MX.
Use XWall or a server that can handle Greylisting on your backup MX.
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Enable Spam Lookup Service - Options->Spam->SLS/RBL
One of the best methods, it catches around 50% of spam
Verifies that the sender uses a valid e-mail domain.
There is no need to accept from e-mail addresses that you can't send to.
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Verify if the recipient - Options->Session->Recipient
Accept only messages for e-mail addresses that really exist on your Exchange.
Often spammer use a list of names and combine the name with your domain and then send a message to every address, hoping that at least a few e-mail addresses are valid.
Due that Exchange send back a non-delivery report for every non-existing e-mail address you end up with thousands of undeliverable message in the outbound queue and so it's better to reject such messages during the SMTP session.
Also XWall needs a lot of CPU power to process all these
messages and you may end up with messages delays and a lot
of messages in MSG-IN directory.
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Enable a heuristic approach to filter out spam mails - Options->Spam->Heuristic
The classification algorithm is based on rules that use a wide range of heuristic tests on mail headers and body text to identify spam messages.
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Enable Image Spam blocking - Options->Spam->Image
Image spam is getting very popular, because it bypasses word based filters.
Enabling this method will block all image based spam.
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Check if the message uses BCC (Blind Carbon Copy) addressing
- Options->Spam->Envelope
Most spam messages are sent as BCC and so this is a very effective way to fight against spam. Combined with a Spam Lookup Service it should catch around 95%.
However, the drawback is that an extensive exclusion list is needs, because not every BCC is a spam. Because of this there is no way to block BCC message in XWall.
Works far better than the simple word blocking, because it is fully dynamic and there is no need to maintain a word list.
Helper Programs
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Signal
Signal is a command line program that allows you to perform the same commands as from the Signal menu of MBAdmin. You can force the download of POP3 messages by simply clicking on a link rather than starting MBAdmin.
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LogView
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.
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TestMX
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.
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ExchImp
ExchImp is a command line program to import Exchange E-mail addresses into datauser.dat for verification of the recipients e-mail address.
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LDAPImp
LDAPImp is VBScript to import AD E-mail addresses into datauser.dat for verification of the recipients e-mail address.
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CSVToEnv
CSVToEnv is a command line program to recreate the envelope from the statistic file. CSVToEnv is needed to resend messages from the history folder.
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TLS/SSL Toolkit
The TLS/SSL Toolkit contains a generic certificate that you may use for a quick start.
Download TLS/SSL Toolkit and extract cert.pem and cacert.pem into the XWall directory and then turn on TLS/SSL.
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Approve-Toolkit
The Approve-Toolkit contains ApproveAction.vbs UDM.vbs and some sample data that you may use as a starting point for your own script that is used in the user defined method or approves the spam method and/or action that XWall triggers.
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SerializeLog by Softec Integrations AG
SerializeLog is a command line program to serialize the XWall logfile to facilitate troubleshooting.
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UniqueLog (beta)
UniqueLog.vbs extracts the part from a logfile that belong to an unique id
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XWALLFilter
XWALLFilter is an add-on even sink to XWall, which automatically routes any
XWall marked message into the Junk-E-Mail folder of Exchange 2003/2007.
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ESATStatus
ESATStatus a utility to show the status of the XWall queues and more wherever you are. Set your warning and alert levels for each individual queue. A quick glance at the screen and you know what's going on.
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ESATInformer
ESATInformer designed for XWall virtually eliminates the "false positive" problem. Daily reports are sent to the email system administrator and all selected users. These reports summarize the spam problem and list each users blocked messages. Using these reports, users can request delivery of any false positives. The request is handled automatically with a summary report sent to the email administrator. With the "false positive" problem out of the way, the XWall spam filters can be tightened to all but completely eliminate spam.
Troubleshooting
Click here to view the troubleshooting section
Licensing Agreement
XWall ® is copyrighted 1993-2008 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 XWall 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.
XWall Standard Edition: DataEnter, (the licensor) grants the buyer (the licensee) the right to use this copy of XWall 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.
XWall ISP Edition: DataEnter, (the licensor) grants the buyer (the licensee) the right to use this copy of XWall ISP 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: Support is by e-mail
Upgrades, Updates: Updates are free, as long as the major version number does not change.
( at present the major version number is v3.x )
Add-On: Add-on are additional or optional parts of XWall that enhance the capability of the core XWall program.
The add-on have their own licensing schema, especially when they are provided by a third-party company.
Central Checksum Service ( CCS ): CCS is an additional optional part of XWall and is licensed on a yearly subscription. CCS uses a lot of hardware and maintenances for the central CCS servers and to cover the cost, the CCS requires a yearly subscription. There was a extensive demo period which expired by the end of 2005 and since then you need a subscription to access CCS.
Trademarks, OpenSSL Credit
History
v3.42 2008-01-19
- New: MBServer is now also available for both the Intel and AMD processors supporting EM64T and AMD64 architectures running on 64bit
operating system like Windows 2003 64bit ( x64 )
- New: Force the application to run in Admin Approval Mode when UAC ( User Account Control ) is enabled in Vista or Windows 2008
- New: Block ecard / postcard ( Options->Spam->Image )
- New: Send statistic ( Options->General->Statistic )
- New: ISP Edition allows different settings for mark subject based on e-mail address or domain
- Chg: Options->Spam->Envelope->Faked MX is no longer in use; use Options->Spam->SPF instead
- Chg: Heuristic checks PQDN and PTR
- Chg: SLS/RBL uses the first IP that is not on the server itself or the backup MX
- Chg: Phishing handles obfuscated URL like
http://www.microsoft.com@5342760458/
- Chg: Exclude from detection of suspicious messages supports wildcards
- Chg: Static route accept a wildcard for the domain
- Chg: XWall no longer changes the codepage to iso-8859-1, because this conflicts with Cyrillic
- Chg: If the subject has no codepage, the codepage of the HTML or body text is used
( Outlook can't display a HTML message where the subject and HTML have a different codepage )
- Chg: Reduced the size of CCS packets so that they better fit into a DNS query
- Chg: Method internal From: automatically excluded for authenticated users
- Fix: Inbound NTLM pass-through authentication on Windows 2003 x64
- Fix: Unicode to ANSI conversion in csv file
- Fix: Illegal ASCII characters are wrong encoded in quoted printable
- Fix: Max worker thread count is exceeded
- Fix: Query for non-existing domains when there is more than one DNS
- Fix: DNS query using UDP with a very fast DNS server
v3.43 2008-08-03
- New: Detect Backscatter ( Options->Spam->Backscatter )
- New: Block DSN/NDR only for specific recipient e-mail address ( Options->Blocking->DSN )
- New: Support for Exchange 2007 X-Auto-Response-Suppress header line
- New: Support for RFC 5064 Archived-At message header
- New: RFC 3834 XWall adds the Auto-Submitted header line and sets DSN to NEVER for Out-Of-Office messages
- New: restart.sig forces a restart of XWall
- New: Setting DSN to NEVER for inbound Out-Of-Office and spam messages
- New: Converting DSN NEVER to a NULL-Sender in the MAIL FROM command, because Exchange sends Out-Of-Office messages back even when DSN is
NEVER
- New: Each record in AdrOWL-A.dat ( white list ) has a human readable timestamp
- New: XWall removes BATV from MAIL FROM address before checking the white list
- New: XWall adds a header line to detect faked DSN
- New: XWall connects to every IP address when the MX host is multi-homed
- New: White List add/del sends back a confirmation message
- Chg: Outbound messages with "auto" in the subject followed by a double dot are not added to the white list
- Chg: A non-delivery report will be sent only when the first MX points to localhost, a backup MX that points to localhost is ignored
- Chg: DNS queries use udp rather then tcp
- Fix: NDR for phishing method shows the reason why the message was blocked
- Fix: Workaround for the Cisco ESMTP-Fixup bug which sometimes fails to mask the ESMTP verbs
- Fix: Failed to connect to the backup MX when the first MX returned a 400 error
- Fix: Error after MAIL FROM with PIPELINING was not reading all data for the following RCPT TO
- Fix: Wrong size limit was announced
- Fix: Decreased DNS recursion because of problems with DNS resolution
- Fix: Ignoring a space when checking for an exploit with double extensions
- Fix: Omit ESMTP STARTTLS when a TLS connection is active
- Fix: Decoding of HTML with hex notation
- Fix: Detect proper HTML codepage when no codepage is defined
- Fix: Admin had a problem reading the certificate list
- Fix: Last line of a Unicode disclaimer file was corrupt
- Fix: GB2312 to Unicode codepage had invalid characters
- Fix: DNS queries with corrupt pointer result in a crash
- Fix: ESMTP PIPELINING with several RCPT TO and all of them get a different error
- Fix: EMSPT SIZE error was skipped
- Fix: Transcript in NDR missed some information
- Fix: Decoding of the attachment filename in an invalid Content-Disposition line
- Fix: Block an outbound e-mail during the smtp session
- Fix: Wrong error in non-delivery-report when MTA responds with 452 Too busy, please try later.
- Fix: Duplicating outbound messages was on domain
- Fix: Service dialog didn't show the correct service name
- Fix: Decoding of Apple Mail with two different codepages for the body text
- Fix: Decoding of messages with UTF-8
Click here to view the complete History
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