E-Mail Configuration: Dial-on-demand (scheduled) Link

Email configuration tips for an HP3000 with a Dial-on-demand Internet connection (via a dial-up router or similar device) where you do NOT want the router dialing except at predefined or scheduled intervals. This is especially useful if the Internet connection is long distance or incurs toll charges when on-line.

Special configuration options include:

• Your HP3000 should be configured with a default gateway in NMMGR. This means your HP3000 must have an Internet-registered IP address. If this is not the case, see the other configuration descriptions dealing with "relaying" mail.
• Your HP3000 should not be configured to point to a (DNS) nameserver.
• You must configure a "trusted gateway" in NetMaint.
• You must add a record in NetMaint's KNOWN-HOST area with the name of the mail relay host (the one your Internet provider supplies), it's IP address, and in the "NETWORK" field on this screen, enter "MODEM". This prevents the background job from automatically delivering outbound mail (all outbound mail must be delivered via a separate process described below).
• You should schedule a job to trigger the opening of the link periodically to allow the Internet Access Provider's machine to download any incoming mail as well as to deliver any outbound mail your system has queued up. Here's a sample job that does just that.
• You should ensure that your Internet Access Provider configure DNS "MX" (mail exchanger) records such that the ISP's machine will accept mail if your system is not "on-line" (if the link is not up).

Note; most dial-up routers support the capability to dial automatically and establish the connection to the Internet whenever they detect a TCP/IP packet bound for a machine not on the local network. Typically they also allow a configurable "timeout" value so they will stay connected for a minimum time period even if no further TCP/IP traffic flows through the link.

Further, incoming mail flowing to your system from the Internet will fall into one of two conditions:

• Your system is on-line (the link is up), then mail gets delivered directly to your system.
• Your system is off-line (the link is down), and mail gets delivered to your ISP's system and queued for later delivery to your system.

In the second case above, most ISP systems are configured to either (1) try to deliver to your system (checking if it's on-line) every 5 or 10 minutes; or (2) configured to automatically start downloading queued e-mail messages as soon as your router logs into their server (i.e. when your link is established).

Native HP3000 Email Server