The Bat! Networking Course

In order to handle E-Mail exchange within either the Internet or a corporate network, each E-mail client should have either a permanent or an on-demand connection with a mail (POP and SMTP) server. A mail server is a computer that processes the distribution and storage of E-Mail messages until they reach their destination address. A generic E-mail client supports at least two of the most commonly used E-mail exchange protocols: POP and SMTP. POP (Post Office Protocol) is used for retrieving mail from a host by a client. Mail message exchange is initiated at the client's request. SMTP (Simple Mail Transfer Protocol) is a simple protocol for mail transmission that is widely used on the Internet. The SMTP server's function is to

receive mail from other servers and clients, and to deliver mail to other hosts and, ultimately, to its clients' mailboxes.

The Bat! can work either as a stand-alone program or as a replacement for a mail (POP/SMTP) server within a local network (e.g. Windows Workgroup, Windows NT Domain or Novell Netware) at the same time as providing the client part. There are three network modes in which The Bat! can function: stand-alone (TCP/IP Workstation), server (TCP/IP or Dial-Out Server )or client (Non-TCP/IP Workstation).

The Bat! acts as a generic e-mail client in this mode. A generic e-mail client must have a connection to its mail (POP/SMTP) server(s), which can be located either inside in the corporate network or somewhere on the Internet. The Bat! can connect to the Internet in one of two ways:

Local Area Network or manual connection. If this connection method is chosen, The Bat! uses the connection to the Internet already established either via your LAN or by dialling your Internet Service Provider. In other words, The Bat! itself does not need to do something extra to connect to the Internet. Some non-LAN systems may be configured so that the ISP is dialled automatically whenever a program tries to connect to an Internet server and this method can be used with The Bat! However, in some cases (combined delivery or multiple account operations), The Bat! has to establish two or more TCP/IP sessions simultaneously and this may cause problems such as trying to establish two dial-up connections at the same time. We recommend using the second connection method if you have a Dial-up connection to your ISP

Dial-Up Networking Connection. You should specify this type of connection if your LAN is not connected to the Internet itself and you are using a Dial-up connection provided by your ISP. Whenever The Bat! needs to open a TCP/IP connection, it checks whether or not the specified 'phone book entry is active (i.e. the established TCP/IP connection, if there is any, has been made using this 'phone book entry). If the entry is active, the TCP/IP sessions start. Otherwise, The Bat! will automatically dial the 'phone book entry to establish a TCP/IP connection. In this case, multiple requests such as checking mail for all accounts and combined delivery (which requires two TCP/IP connections to be open at once: one for mail retrieval and another one for sending mail) will be handled correctly.

It is possible that client computers in a local network have no access to the Internet or that there are some restrictions in force that prevent these computers from using mail transfer protocols. In order to provide users of such machines with E-Mail exchange facilities within the Internet and/or the corporate network, there must be a mail (POP/SMTP) server within the workgroup or domain.

The Bat! in server mode can replace a mail server for such a network. This means that it enables you not to need a mail server inside your local network and, moreover, it gives users the possibility of processing E-Mail exchange over the Internet without having their own Internet connection. A computer with The Bat! in server mode is basically the same as in stand-alone mode with the addition of the use of its own Internet connection to provide E-Mail exchange with computers with The Bat! in the client mode over the network and/or the Internet.

The Bat! in client mode uses neither Internet nor local connection to a mail (POP/SMTP) server for E-Mail exchange. It uses The Bat! in the server mode within the network to which it belongs. There is no limit on the number of computers which can run The Bat! in client mode within a network as long as the server machine is unique for each group of client machines. This latter point also means that it is possible to have several groups of client machines using different servers but those groups cannot intersect.

All account data and message bases that are used by computers in client mode are located on the server computer and the data is accessed using the local network.

When the user of a client machine wants to send a message to an Internet address, it places the message into the Outbox which is physically located on the server machine. It then sends the command that makes the server send the outgoing messages using the server's connection to the Internet.

When a client wishes to check its POP account, it sends the command to the server to check the client's mailbox on the mail server. The server connects to the POP server using its own Internet connection, receives the messages, stores the messages in the client's message base and sends the command to the client to re-read its message base contents. When the client receives this command, it notifies the user that the new mail has arrived. The new message arrival is indicated in the folder tree screen of the client, and on the MailTicker , if the MailTicker is configured for use.

To turn on the MailTicker (there must be some unread messages for the MailTicker to scroll), use the "Options | MailTicker | Show Always" or "Show Automatically" options of the main window menu.

1.	Within your local network, select a computer, which is connected to the Internet. This computer will be the "TCP/IP or Dial-out Server" (server).

Using the "My Computer" desktop icon, choose the local drive or directory in which The Bat! is installed or where you are planning to install The Bat!. This location will be used to store the message bases. Make this path available as a "network share" for the users that are going to run The Bat! in client mode on their computers. If you are already using a network drive, e.g. on a dedicated file server, you may skip this and the next step.

3.	Map the shared resource from step 2 to a network drive letter. Other computers that are going to act as clients within your network will use this network drive to exchange information with the server.

4.	If you do not have The Bat! installed yet, install it to the mapped network drive in order to allow machines running The Bat! in client mode to access it. Run The Bat! from the newly mapped network drive.

5.	Click the "Network & Administration" item of the "Options" menu to make sure that this machine is in "TCP/IP or Dial-Out Server" (server) mode.

6.	Create the accounts that will be used by the client machines. Make sure that the home directories of these accounts are located on the network drive so that the client users can access them.

7.	Invoke the "Network & Administration" dialog box again and configure the privileges of the accounts you have created.

1.	Map the shared resource from the server to the same drive letter as it is mapped to on the server.

2.	When installing The Bat! on a client machine, select the program's working directory on the network drive letter that you have just mapped. The working directory must be the same as that on the server.

3.	If you have already The Bat! installed on this computer, please perform the following steps, otherwise, if you just have installed The Bat! according to the previous steps, the setup is complete.

These sub-steps describe how to change the machine from stand-alone to client mode without having to reinstall The Bat! If you are not familiar with the use of RegEdit, it would be better for you to uninstall The Bat! and to go to the step entitled "Installing The Bat! on a client computer"

1.	Open the "Network & Administration" dialog box and make sure that this machine is set up as a "Non-TCP/IP Workstation".

Change the mail directory using RegEdit. Open RegEdit and navigate to the HKEY_CURRENT_USER\Software\RIT\The Bat! key, look for the entry called "Working Directory". The value data is the path to the mail directory, which should be changed to match the network drive, and it made the same as that on the server.

There may be reasons to have an E-Mail Exchange system for local corporate networks that have neither POP/SMTP servers nor Internet access. In this case, there must be a local message delivery system, i.e. the messages must be routed, delivered and stored locally without using POP/SMTP servers.

Local Delivery Technology is provided by The Bat! when the appropriate option is turned on. To activate it, open the "Network & Administration" dialog box on the server, and tick the "Allow Local Delivery" checkbox. This option allows several machines to work in a local network exchanging messages without using n SMTP/POP server at all. This feature provides a very efficient solution for building corporate mail-exchange networks without using Internet Mail Transfer Protocols. When the "Allow Local Delivery" option is on, outgoing messages addressed to local users are delivered directly into the appropriate message bases instead of having to send them to an SMTP server.