3.00
MS-DOS
kb3rdparty
The information in this article applies to:
- Microsoft Mail Gateway to SMTP, version 3.0
SUMMARY
When you have the SMTP Mail Gateway functional, you need to address several
factors to get reliable performance. If you overlook the factors, the
gateway may intermittently hang and refuse inbound connections.
The issues listed below are usually involved when the gateway stops working
with no error message recorded in the SMTPGATE.LOG, and the following is
repeatedly displayed in this file:
Spawning SMTPGET
Spawn(SMTPGET)=0
Idling: 48258 bytes, largest 47234
MORE INFORMATION
The following five configuration issues can decrease the reliability of the
SMTP gateway.
- The postoffice (PO) and gateway should be on the same physical network.
Because the gateway's temporary files are written on the
postoffice (M:\MAILDATA\SMTP\), and not its local hard disk, the
performance of the gateway is dependent on file input/output.
The most effective way to ensure fast file input/output is to
have both the gateway and postoffice on the same physical
network.
- Use a Mail Relay Host for inbound SMTP mail.
It is not mandatory to have Mail Relay Host configured for Inbound
mail, but it is highly recommended. The SMTP Gateway is dependent
on a MS-DOS redirector and the reliability of a UNIX to MS-DOS
connection is not as robust as that of a UNIX to UNIX connection (UNIX
is multithreaded; MS-DOS is single threaded). Therefore, you should
control the UNIX to MS-DOS connection by storing all messages going to
the Microsoft Mail on a Host before they get forwarded to Microsoft
Mail.
You want to have as much control over the less reliable UNIX to MS-DOS
connection as possible. The optimum way to control this is by putting a
Mail Relay Host on the same network segment as the gateway and PO
server. Not only does this increase the reliability of the UNIX to
MS-DOS connection from a physical perspective, but it also allows the
Host to be configured to open/close the connections more effectively.
- Routers should use static routing.
If the Smart Host (Mail Relay Host) is not on the same network
segment as the gateway and PO, then static routes should be
configured on the router that separates the gateway and host.
The IP addresses for the gateway and the Smart Host should be
added to the static table on the router.
NOTE: Most routers use dynamic routing by default, a static table
needs to be manually created and maintained.
- Use a 16-bit network interface card (NIC)
When you use a 16-bit NIC, it is a good way to get fast file
input/output. Additionally, it is recommended to use a 16-bit NIC
with RAM disabled.
- Use one protocol per NIC (IPX/SPX)
When the PO is on a Novell NetWare server, and IPX/SPX is used to
access the PO and TCP/IP is used to access the Host, it
may be necessary to isolate each protocol on a separate NIC.
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