Unable to integrate Vontu E-mail Prevent with Lotus Notes Gateway.
421 4.4.1 Fatal: Forwarding agent unavailable. Closing connection.
Make sure that upstream MTA listens on Port 25 to the E-mail Prevent Server.
Steps to conform the port listening issue :-
Try to telnet from Upstream MTA to e-mail prevent on port 25.
Details about Network Prevent (Email) Server operating in forwarding mode are as follows:
■ The upstream MTA SMTP listener receives a message.
■ The upstream MTA routes the message to the Network Prevent (Email) Server SMTP listener on TCP port 25. (By default, the configured TCP port number is 10025, but it is recommended to change this to 25.)
■ The Network Prevent (Email) Server inspects the message and, if the server does not block the message (based on a configured policy), it proxies the message to a downstreamMTAor hosted email server. The IP address address for this next hop in the message chain can either be specified in the Network Prevent (Email) Server configuration or obtained through anMXrecord lookup of a configured domain name.
■ The downstream MTA or hosted email server sends the SMTP message to the next-hop MTA hosted mail server. A hosted email service may perform additional tasks, such as detecting viruses in the message or encrypting the message contents, before proxying to the receiving MTA.