You can configure your CommuniGate Pro Server SMTP module to use secure (encrypted) connections when sending messages to certain remote sites. This feature is especially useful if your company has several offices and E-mail traffic between the offices is sent via the public Internet.
You should simply list the domain names that should receive mail from your server via secure connections:
The specified names can contain a wildcard - the asterisk (*) symbol.
When the CommuniGate Pro SMTP module connects to a relay of one of the listed domains, it checks if that relay supports the STARTTLS protocol extension command. Then the SMTP module uses this command to initiate a secure connection with that relay.
The CommuniGate Pro SMTP module checks the validity of the remote relay Certificate using the specified set of the Trusted Certificates. The remote relay Certificate subject must contain the cn (Common Name) field that matches either the domain name of the remote site, or the name of this relay. This can often cause a problem, since the domain company.dom may have the MX record relay1.company.dom, but the computer with the relay1.company.dom address has the "main" DNS name smtp.company.dom and its Certificate is issued to that name (its Certificate subject contains smtp.company.dom in the cn field).
To solve this problem, you should explicitly route all traffic to the company.dom domain via the smtp.company.dom relay, using the following Router record:
NoRelay:company.dom = firstname.lastname@example.org._via
Note: this feature ensures that messages between your server and a remote relay are transferred securely. To provide complete end-to-end security, you should verify that:
If the domain is listed in the Send Secure To Domains list, and the receiving server does not support the STARTTLS command, or the remote server certificate cannot be validated, or the remote server certificate Subject does not match the domain or domain relay name, all messages to that domain are rejected, ensuring that no message is sent via a potentially insecure link.
If your server sends all outgoing mail via a forwarding server, you can enter the asterisk (*) symbol into the Send Encrypted field to encrypt all communications with the forwarding server. The CommuniGate Pro SMTP module does not check the Subject of t