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KB08122901 Troubleshooting client connections


Inbound Problems?
If you are having a problem getting mail into Mailtraq from the Internet see this KB Article for step-by-step solutions to routing problems.  

KB06020901 Resolving inbound/outbound mail problems...

Client Connection Problems

Or - I can't get Outlook to connect to Mailtraq

In most cases there is no difficulty in connecting Outlook to Mailtraq, but sometimes you cannot get access, and this article will help you solve those problems.

This KB article refers to solving problems connecting Outlook to Mailtraq, but the same principles apply to all email client connections.

Selecting your Protocol - POP3 or IMAP

All editions of Mailtraq support POP3 connections from Outlook.
Mailtraq Professional, the most popular edition, also supports IMAP

In this article we will troubleshoot an IMAP connection, but again the same principles apply when solving POP3 connection problems. The main difference, for troubleshooting, is that IMAP connects on Port 143 and POP3 connects on Port 110.



Make sure the service is running in Mailtraq

The 'Active Connections' entry in the Console shows which ports Mailtraq has available.

Mailtraq should be offering by default connections for

  • SMTP on Port 25,
  • POP3 on Port 110,
  • HTTP Webmail on Port 80, and
  • Instant Messaging on Port 5222

The IMAP service does not install by default - you need to enable IMAP

Make sure that other programs are not already using ports that Mailtraq will need to handle your mail.
If Mailtraq finds these ports in use when it starts then those sevices will be closed in Mailtraq. It is essential that Mailtraq has access to these ports to be able to offer mail services.  

Make sure the LAN is defined in Mailtraq

This tab appears in the Server Properties dialog and is used to define the range of IP addresses and hosts which represent the machines on a local network.

It is accessed from the Console, at Options | Server

This is one of the most important settings in Mailtraq as it is used in many places as the default method to control access to services.

If you do not have your LAN correctly defined Mailtraq will refuse the connection from your client.

If you are trying to connect clients that are outside the LAN (for example - to a Mailtraq that is remotely hosted) please read the general FAQ page for tips on problem solving. 


Make sure you have a User defined in Mailtraq and you know the username and password - read more


Make sure Outlook is connecting to the correct server

You may connect either by IP address (as illustrated) or by machine name. If you are troubleshooting a connection then use the known, fixed, LAN (local) IP address of the Mailtraq machine

Make sure you have selected the correct protocol

In the Outlook Account Type dialog select IMAP (or POP3) from the drop-down list.

Make sure your account is set up to access the known user and password

This must match the user name and password set up in Mailtraq (see above)
Note that the user name is not the full email address - only enter the portion of the address to the left of the @ symbol. In the above example you would enter  -  jsmith

Testing your connection

If your configuration is correct, but you still cannot access Mailtraq from Outlook then it is most likely to be a firewall or anti-virus issue.

How to check your IMAP connection

Use Telnet* to check your connection

How to use Telnet -
Telnet for Windows 7, Windows 10, Windows 2008, Windows 2012, and Vista ...


The 'Telnet' test
If you cannot 'manually' connect to the Mailtraq machine on Port 143, then neither can your email clients - so you'll need to look to the way your network, firewall or routers are configured.

Before starting any testing ensure that the service you are testing, in this example IMAP on Port 143 has been created and started so that it shows as 'Active = Yes' in the console.

If the service starts and then stops (Active = No) that indicates the port is already in use by some other application.

If you can connect, but don't get Mailtraq mentioned in the 'banner response' like the examples below, then some other program is using the port. You will either have to stop that program, change the port it is using, or change the port that Mailtraq wants to use. It essential for Mailtraq to have exclusive access to Port 143 for successful connections.

Mailtraq accepts connections on the loop-back address of by default, but you should check that you have not removed this ability. Look at Options | Server and you should see listed in the Domain Alias ... box. If it is not there, replace it as illustrated.

1.) See if you can connect to your Mailtraq from the same machine - you can use the loop-back IP address of,   This proves that Mailtraq is providing an accessible IMAP service

For example, at a Command prompt on your client machine entering: telnet 143
should give a response something like this:
* OK IMAP4rev1 Mailtraq ( ready

2.) See if you can connect to your Mailtraq machine - which has, for example, a local IP address of - from another machine on your LAN.

For example, at a Command prompt on your client machine entering: telnet 25
should give a response something like this:

* OK IMAP4rev1 Mailtraq ( ready

You can also Telnet to other ports to check their connectivity: Port 110/POP3, Port 80/webmail, Port 25/SMTP and so on.

If you don't seem to be able to Telnet on Port 143 at all, then you will need to adjust your Firewall and your Router to allow connections. Read more here: KB06020901 Resolving inbound/outbound mail problems 

Using the Mailtraq Event Log

Full details of accessing and using the Mailtraq Event Log are detailed here ...

The Event Log viewer provides a useful diagnostic tool by showing inbound connections to Mailtraq.

To make it easier to see what is happening, restrict the display to just show Connections by only selecting the Connections-button in the top-row.

Then perform your tests, and watch for a matching inbound IMAP connection in the log entries. 

*Using Telnet

This example uses Port 143 for IMAP. The same method works for other standard ports, such as Port 25 for SMTP, Port 110 for POP3 etc

To use Telnet, go to Windows | Start, Run and enter cmd in the box then [OK] - a black window will open with a flashing command prompt.  Type the following example: telnet<space>IP address<space>port number, like this:

telnet 143

and you should get a response like: * OK IMAP4rev1 Mailtraq ( ready

If you are not familiar with Telnet then you can find information about using it here.

W10/W8/W7/Vista users:

These versions of Windows come with a Telnet client but it is not enabled by default. So:

1. Open the Windows Control Panel
2. Select Programs and Features
3. Select Turn Windows Features on or off
4. May need to confirm the action
5. Wait... this can take a while while the list populates
6. Click the checkbox beside the telnet client
7. Click [OK] ... this can take a while

- now you can use Telnet as described above

W2008/W2012/W2016/W2019 Server users:

  1. Start Server Manager. Click Start, right-click Computer, and then click Manage.

  2. If the User Account Control dialog box appears, confirm that the action it displays is what you want, and then click Continue.

  3. In the Features Summary section, click Add features.

  4. In the Add Features Wizard, select Telnet Client, and then click Next.

  5. On the Confirm Installation Options page, click Install.

  6. When installation finishes, on the Installation Results page, click Close.

Testing from outside your network

If you need to see if your Mailtraq is accessible for SMTP access on Port 25 from the Internet you must test to your public facing IP address from a location outside your own local network (LAN). You can do this from a neighbor or from your home Internet connection.

Using a smartphone to test connection

If you have a current Android phone you can use a free app - Simple Telnet Client

How to use

Simply enter the public facing IP address from your installation in the box named 'Hostname' in the example.

Change the Port from 23 to 25.

Click the Connect button.

For example:

Entering the following

[]  [25]    will result in  <Connecting> then after ~20 seconds:

<220 Ready for action (Mailtraq>


You must test your connectivity using using YOUR Public facing IP address.


Your Public facing IP address must match the MX record reported by IntoDNS or similar DNS reporting tools. For example:

Keywords: kb client troubleshooting
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