This article explains how ipMonitor sends emails or SMTP messages.
SMTP messages are relayed from the ipMonitor installation by using the following procedure:
- If the "Optional SMTP relay server" field is specified under "Server Settings," ipMonitor will attempt to relay messages through this server first.
- If the SMTP relay server connection fails or is not specified, ipMonitor will use MX records through DNS queries to find a list of potential mail servers. If a DNS server is specified in the "Optional DNS override server (for MX records)" section under "Server Settings," then ipMonitor will connect to this DNS server to retrieve MX record information for the recipient domain. If a server is not specified, ipMonitor will use the DNS servers configured for the ipMonitor server's network connection.
- When the MX records are retrieved, ipMonitor will attempt to connect to each server listed, in order of MX preference.
- The relay procedure will complete with a successful transmission to one of the potential relay servers or will exhaust the MX records and fail to relay the message.