POP3 Connector for Microsoft Exchange and Lotus Domino with Anti-Spam Filter and Anti-Virus Protection: PYTHEAS MailGate

POP3 Connector / POP3 Gateway for Microsoft Exchange 2010

Be sure to use PYTHEAS MailGate v.2.41 or later - its Configuration Wizard has special support for Microsoft Exchange 2010. PYTHEAS MailGate will interact with an Microsoft Exchange 2010 server holding the Hub Transport role.

Configure incoming mail flow

1. Connections to the existing Receive Connector

By default, Microsoft Exchange requires authenticated connections to its default Receive Connector. Since version 2.70, PYTHEAS MailGate can authenticate to the Exchange Receive Connector.

So either...

  • do the following to allow anonymous connections to the Receive Connector: in the Microsoft Exchange 2010 management console, go to Server Configuration / Hub Transport, open the properties of the Default... Receive Connector, switch to the Permission Groups page. Tick the Anonymous users checkbox.


  • configure authentication credentials on the Your mail server page of the Configuration Program ,

2. Make the maximum message size visible in the ESMTP response

Configure the Receive Connector with the following Exchange Management Shell command:
Set-ReceiveConnector -id "Default Your_Server" -SizeEnabled Enabled
If you are not sure about the name of the Receive Connector, use the Get-ReceiveConnector command to get a list.

3. Allow incoming messages sent to your messaging domain

In the Microsoft Exchange 2010 management console, go to Organization Configuration / Hub Transport, the Accepted Domains tab.

  • If you have your own messaging domain (like company.com): if you see it in the list, skip the rest of this section. If you don't, add your messaging domain to the list: Create a New Accepted Domain for your messaging domain, with type Authoritative Domain.
  • If you do not have your own messaging domain (i.e. your users have email addresses like user@your-isp.com), create a New Accepted Domain for the domain your-isp.com, with type Internal Relay Domain.

4. Other settings you may want to check

Spam filtering

By default, spam-filtering is not enabled on a server with the Hub Transport role. In this case you may skip this section. However, if spam filtering is enabled on the Hub Transport where the above Receive Connector belongs to (you will recognize Anti-Spam tabs in this case), make sure to add the IP Address of the machine where PYTHEAS MailGate is running, to the Green IP List (in Server Configuration, Hub transport). If both are on the same machine, use

On the other hand, if you want to use the Microsoft Exchange 2010 spam filtering capacities, do not add the above IP address to the Green IP List. However, make sure that messages recognized as spam are always accepted, so do not use the Reject messages... option on Organization Configuration / Hub Transport / Content Filtering / Action. Beginning with v. 2.74, you may also proceed as described here.

Maximum message size

By default, the Exchange Receive Connector accepts messages with a maximum size of 10 MB. In many cases, you may want to set a higher limit (Exchange Management Console, Server Configuration, Hub Transport, Receive Connector , Default...<server name> or Default_SBS_Internet_Receive_Connector_<server_name>, Properties). You may want to read this, too...



Configure outgoing mail flow

If you do not want PYTHEAS MailGate take care of outgoing email, you may skip this section and organize outgoing mail flow according to your requirements in Microsoft Exchange 2010. On the other hand, if you want PYTHEAS MailGate take care of outgoing mail, please do the following:

Create a new Send Connector

  • If you already have a Send Connector to send email to the Internet, you may consider removing it and create a new one, or modify it according to the instructions below.
  • In the Microsoft Exchange 2010 management console, go to Organization Configuration / Hub Transport, the Send Connectors tab. If the list is empty, create a new Send Connector with the following characteristics:
    • Name: ToPytheasMailgate (you can choose any name);
    • Intended usage: Custom;
    • Address spaces: click Add then enter * (a single asterisk) as the domain name. Don't care about the state of theInclude all sub domains checkbox ;
    • Network settings: choose Route mail through the following smart host, then click Add, then add the IP address of the machine which will be running the PYTHEAS MailGate Communication Task to the list . You may use if it's on the same machine. Leave the Use the External DNS Lookup settings on the transport server box unchecked.
    • Smart host security settings: choose None
    • Source Server: Your Exchange server should already be in the list.
  • If both Microsoft Exchange 2010 and PYTHEAS MailGate run on the same machine, you will need to change the outgoing SMTP port of the Send Connector:
    • Open the Microsoft Exchange Server 2010 Management Shell from the Start Menu.
    • Paste the command
      Set-SendConnector -identity "ToPytheasMailgate" -Port:2500
      into the management shell window, and execute it. This will change to outgoing SMTP port to 2500.
    • You may check the new configuration with the following command:
      Get-SendConnector -identity "ToPytheasMailgate" | Format-List
      giving the following result:
      AddressSpaces                : {SMTP:*;10}
      DNSRoutingEnabled            : False
      DomainSecureEnabled          : False
      Enabled                      : True
      Identity                     : ToPytheasMailgate
      MaxMessageSize               : 10 MB (10,485,760 bytes)
      Name                         : ToPytheasMailgate
      Port                         : 2500
      SmartHostAuthMechanism       : None
      SmartHosts                   : {[]}
      SmartHostsString             : []
      SmtpMaxMessagesPerConnection : 20
      SourceIPAddress              :
      UseExternalDNSServersEnabled : False
      Note that you won't see any change in the graphical user interface of the management console.
  • By default, the Exchange 2010 Management Console sets a maximum message size of 10MB for outgoing messages through this send connector ; you can change this limit in the graphical user interface.

Limit de number of outgoing connections

  • In the Microsoft Exchange 2010 management console, go to Server Configuration, and open the Properties, Limits tab. In Connection Restrictions, set both the Maximum concurrent outbound connections and the Maximum concurrent outbound connections per domain to 1.
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