MultiSendcon Configuration: Master Relay

This is the Master relay configuration dialog in MultiSendcon. Here you can define the IP and port number that the MultiSendcon.master relay server is reachable for your Exchange Server and also limit access to this master relay to specific IP addresses to keep your MultiSendcon installation from being abused as a spam relay.

MultiSendcon works as a "master SMTP relay server" installed locally on your server. Microsoft Exchange just forwards all emails to this master relay server. MultiSendcon then distributes these emails immediately to the relevant outside relay server according to the sender address. That is also the main difference between the handling of multiple relay servers in Exchange and MultiSendcon: Exchange allows multiple "send connectors" but only selects the send connector according to the recipient domain. MultiSendcon adds the capability to select a specific relay server according to the SENDER address. In addition to that, MultiSendcon also allows using different specific local IP addresses in Systems that have multiple local IPs.

You can configure the individual relay servers that MultiSendcon forwards your email to on the next configuration page, "RelayServers".MultiSendcon master relay server:

• Local IP Address: This is the local address that the MultiSendcon master relay server binds to. You need to point your Exchange send connector to this IP.
• IP port: Usually SMTP servers answer on port 25, but since that port is already used by the Exchange receive connectors you should select a different port for the MultiSendcon master relay server. Our default is port 2500 because it's easy to remember and not usually occupied. But any free port would do.
  

Limit access to certain IP addresses:

Define the IP address ranges that you want to allow access here. If this feature is activated MultiSendcon will only accept incoming connections from these IP addresses. Best practise is to limit access to only your Exchange Server's IP