Internet Shopper - List Server for NT

This page will sketch out the preliminary plans for the List Server that is about to be written to go with the NT Mail service.

Introduction
List Maintenance
Mail Propagation
List Parameters
Global Parameters
Comments

Introduction

The list server will be an "add on" feature to the mail program and actually be part of the SMTP service. There are two parts to a list server, the list maintenance and how mail is propagated. The list maintenance will be carried out by mailing to a designated user on the NT machine. The SMTP service will intercept this mail and attempt to interpret the commands it contains. When someone mails to the list name at the NT box, the mail message will be propagated to every user who is currently in the mail list.

Each list will have a set of parameters which define who is allowed to post, subscribe, etc. These parmeters are indicated in italics in the rest of this document and summarised at the end.

List Maintenance

The list will be maintained by sending mail messages to the list server which will be called list for the rest of this document (although the name will be configurable). The list server will read the message and execute the first command in the body of the message. The command may be one of HELP, SUBSCRIBE, UNSUBSCRIBE.

HELP

When used on its own, causes a file called help_mes to be sent to the "From:" clause of the mail message. If the message is bounced, the message will be discarded.

When the command has a valid list name and the "From:" clause matches the list_member_allow a file called list_help_mes will be sent to the "From:" clause of the mail message. This file is defined for each individual list and should (at a minimum) contain details about what the list is for and how to leave the mail list.

This command takes one parameter, the name of a list. If this list exists and the "From:" clause matches the list_member_allow, the user will be added to the mail list and the message in list_join_mes will be sent to the new list member. From this point on, any mail messages sent to the list will be propogated to this new list member.

UNSUBSCRIBE

Propagation of mail

To send a message to every user of the mail list, simply send a mail message to the list@domain. The SMTP Service will look up the list and send a message to each person found on it. For security purposes, the "From:" clause of each message will be matched against a list_post_allow parameter first.

If any messages are bounced, the destination will be removed from the list of members to that mail list.

List Parameters

The following parameters will be defined for each mail list:

list_member_allow

This is a semi-colon seperated, wildcarded list of strings which the "From:" cause of any subscribers will be verified against. In the simplest case, an "*" will allow any person to be a member of the list.

For example, by using "*@net-shopper.co.uk" you can create a list that can only be subscribed to by people within Internet Shopper Ltd. and by using "*uk;*edu" you could create a list that allows access to those people who have a mail address ending in "UK" or "EDU" (if you were so inclined).