1.TCPIP> SHOW MX_RECORD SWAN
BIND MX database
Server: 18.18.218.10 GREAT.HORNED.OWL.COM
Gate address Preference Gate name
18.18.218.10 50 WATER.PIPIT.WEBBED.FEET.COM
18.1.218.16 100 bd-gw.purple.martin.com
188.88.206.2 200 great.horned.owl.com
199.9.214.1 300 bird.food.seeds.worms.com
BIND database
Server: 18.18.218.10 WATER.PIPIT.WEBBED.FEET.COM
Host address Host name
18.18.100.10 SWAN.WEBBED.FEET.COM
Displays, in order of preference, the routing hops to reach
host SWAN if an attempt fails. The local host tries to route
through:
1. WATER.PIPIT.WEBBED.FEET.COM
2. bd-gw.purple.martin.com
3. great.horned.owl.com
4. bird.food.seeds.worms.com
Both the alternate gateway and the zone affect how SMTP
determines where to relay nonlocal mail.
MX records tell mailers where to relay mail that is destined
for a given host. In the display:
o The Gate name field tells where to relay the mail.
o The Gate address field gives the gateway's IP address.
o The Preference field gives each MX record a precedence. A
lower preference number means a higher precedence.
2.TCPIP> SHOW MX_RECORD CROW.COM
BIND MX database
Server: 18.18.218.10 WATER.PIPIT.WEBBED.FEET.COM
Gate address Preference Gate name
159.228.12.253 1 cawcaw.crow.com
159.228.12.254 2 scare.crow.com
TCPIP>
Displays the MX record for destination host crow.com. In the
display:
o The Gate name field tells where to relay the mail.
o The Gate address field gives the gateway's IP address.
o The Preference field gives each MX record a precedence. A
lower preference number means higher precedence.
In this example, the local host name is WATER, the alternate
gateway is scare.crow.com, and the zone is crow.com. The
first preference for delivering mail to crow.com is to send
to cawcaw.crow.com.
If you have not defined an alternate gateway, SMTP tries to
relay the mail to scare.crow at IP address 158.228.12.253. It
uses the MX records to determine the host to which to relay
mail. SMTP tries to relay the mail to each gateway host, in
order of preference, until it either successfully transfers the
mail or runs out of MX records to try. If there is no alternate
gateway, the zone is not used.
If you have defined an alternate gateway, SMTP goes through
the list of MX records, but it does not automatically try to
relay the mail directly to the gateway. SMTP checks whether
the gateway host name is outside or inside the SMTP zone (as
defined with SET SMTP CONFIGURATION). If the gateway is inside
the SMTP zone, SMTP tries to relay the mail directly to the
gateway host. If the gateway is outside the zone, SMTP sends
the mail to the alternate gateway.