DNSGETMX
[/?]
[/SERVERIP address]
[/SERVER name]
[/SERVICE name]
[/WELLKNOWNPORT port]
[/CLIENTIP address]
[/CLIENTPORT port]
[/IP6[+|-]]
[/IMPLICIT[+|-]]
[/SRV_SUPERDOMAINS[+|-]]
[/SRV_SELF[+|-]]
[/FETCHGLUE[+|-]]
[/IP6ADDR[+|-]]
[/B[+|-]]
domain
The DNSGETMX command obtains the IP addresses, ports, priorities, and weights of the SMTP Relay servers for the domain domain. It prints them all, one per line, to its standard output.
DNSGETMX performs the standard server lookup procedure that would be performed by the SMTP Relay client utility, printing the results of the server lookup rather than contacting the servers for actual SMTP Relay service. Its service name, transport name, and well-known port number are the same as those used by the SMTP Relay client.
Lookups are performed by contacting a proxy DNS server. DNSGETMX uses the same DNS client library as applications (and the other service client utilities in the Internet Utilities) use, and so the proxy DNS server contacted is by default the same proxy DNS server as all applications use.
Although DNSGETMX can thus be reconfigured to talk to other DNS servers and
to bind the client ends of its sockets to specific IP addresses and port
numbers using
the DNS client library's ordinary configuration environment variables,
for convenience the
/SERVERIP,
/WELLKNOWNPORT,
/SERVER,
/SERVICE,
/CLIENTIP, and
/CLIENTPORT
command-line options can also be used to do the same thing, overriding the
configuration environment variables.
If all IP addresses are obtained successfully, DNSGETMX exits with a zero code. Otherwise it exits with a non-zero code.
/B