TESTMXLOOKUP(1) | Double Precision, Inc. | TESTMXLOOKUP(1) |
NAME¶
testmxlookup - Look up mail relays for a domainSYNOPSIS¶
testmxlookup
[@ ip-address] [--dnssec] [--udpsize n]
{domain}
DESCRIPTION¶
DIAGNOSTICS¶
The error message "Hard error" indicates that the domain does not exist, or does not have any mail relays. The error message "Soft error" indicates a temporary error condition (usually a network failure of some sorts, or the local DNS server is down).OPTIONS¶
@ip-addressSpecify the DNS server's IP address, where to
send the DNS query to, overriding the default DNS server addresses read from
/etc/resolv.conf.
“ip-address” must be a literal, numeric, IP address.
--dnssec
Enable the DNSSEC extension. If the DNS server
has DNSSEC enabled, and the specified domain's DNS records are signed, the
list of IP addresses is suffixed by “(DNSSEC)”, indicating a
signed response.
This is a diagnostic option. Older DNS servers may respond with an error, to a
DNSSEC query.
--udpsize n
Specify that n is the largest UDP
packet size that the DNS server may send. This option is only valid together
with “--dnssec”. If “--dnssec” always returns an
error, try “--udpsize 512” (the default setting is 1280 bytes,
which is adequate for Ethernet, but other kinds of networks may impose lower
limits).
SEE ALSO¶
AUTHOR¶
Sam VarshavchikAuthor
NOTES¶
- 1.
- courier(8)
[set
$man.base.url.for.relative.links]/courier.html
- 2.
- RFC 1035
11/18/2011 | Courier Mail Server |