Sendmail Pauses for Up to a Minute at Each Command

Sendmail Pauses for Up to a Minute at Each Command

Make sure that Sendmail can resolve your hostname to a valid (i.e.,
parsable) domain address. If you are not connected to the Internet, or
have a dial-up connection with dynamic IP addressing, add the fully
qualified domain name to the /etc/hosts file, in addition to the base
host name; e.g., if the host name is "bilbo" and the domain is
"bag-end.com:"

192.168.0.1 bilbo.bag-end.com bilbo

And make sure that either the /etc/host.conf or /etc/resolv.conf file
contains the line:

order hosts,bind

Caution: Do not change the "localhost" entry in /etc/hosts, because
many programs depend on it for internal message-passing.

Sendmail takes many factors into account when resolving domain
addresses. These factors, collectively, are known as, "rulesets," in
sendmail jargon. The program does not require that a domain address be
canonical, or even appear to be canonical. In the example above,
"bilbo." (note the period) would work just as well as
"bilbo.bag-end.com." This and other modifications apply mainly to
recent versions.

Prior to version 8.7, sendmail required that the FQDN appear first in
the /etc/hosts entry. This is due to changes in the envelope address
masquerade options. Consult the sendmail documents.

If you have a domain name server for only a local subnet, make sure
that "." refers to a SOA record on the server machine, and that
reverse lookups (check by using nslookup) work for all machines on the
subnet.

Finally, FEATURE configuration macro options like nodns,
always_add_domain, and nocanonify, control how sendmail interprets
host names.

The document, Sendmail: Installation and Operation Guide, included in
the doc/ subdirectory of Sendmail source code distributions, discusses
briefly how Sendmail resolves Internet addresses. Sendmail source code
archives are listed at: http://www.sendmail.org/

[Chris Karakas]


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