The SMTP protocol is used to receive messages from the Internet and from the client mailer applications. If you want to receive messages from the Internet, you need a TCP/IP link to the Internet, and your server domain name and the IP address should be included into the DNS records.
Click the Receiving link on any SMTP Settings page to open the SMTP Receiving settings page.
Channels: When you specify a non-zero value for this setting, the SMTP module creates a so-called "listener". The module starts to accept all SMTP connections that other mail servers establish in order to send mail to your Server. This setting is used to limit the number of simultaneous connections the SMTP module can accept. If there are too many incoming connections open, the module will reject new connections, and sending mail systems will retry later.
Listener: This link allows you to tune the SMTP [Listener](https://support.communigate.com/en/guides/communigate-pro-manual/network-2/listeners
). You can specify which TCP ports to use for SMTP incoming connections (by default, the port 25 is used), which local IP addresses to use for incoming connections (all available addresses are used by default), and which remote addresses should be granted access to your CommuniGate Pro SMTP Server (by default, all addresses can connect to the SMTP port). Note: to allow Microsoft® Outlook Express 4.x users to submit messages using secure connections, you should configure the SMTP listener to accept connections on the TCP port 465, and enable the SSL/TLS option for that port. Note: Netscape® Messenger and modern versions of Microsoft Outlook and Outlook Express products do not need any special port for secure communications, since these products use the STARTTLS command to initiate secure communications after establishing a regular, clear text SMTP connection to the standard port number 25.
Advertise AUTH capability: If a server reports (in its initial EHLO prompt) that it supports SMTP Authentication, some mailer clients force users to authenticate themselves before sending messages. If you select the Non-Clients value, and a connection is accepted from an address included into the Client IP Addresses list, the SMTP module will not report that it supports the AUTH command. If the Nobody value is selected, the SMTP module never reports that it supports SMTP AUTH. This option does not disable the SMTP Authentication feature itself.
Advertisement 8BITMIME: If your Server does not report the 8BITMIME capability, some mailers and servers will MIME-encode all non-ASCII messages that they send to your Server . This server