etrn - start mail queue run
etrn [-v] server-host [client-hosts]
SMTP's ETRN command allows an SMTP client and server to
interact, giving the server an opportunity to start the pro-
cessing of its queues for messages to go to a given host.
This is meant to be used in start-up conditions, as well as
for mail nodes that have transient connections to their ser-
The etrn utility initiates an SMTP session with the host
server-host and sends one or more ETRN commands as follows:
If no client-hosts are specified, etrn looks up every host
name for which sendmail(1M) accepts email and, for each
name, sends an ETRN command with that name as the argument.
If any client-hosts are specified, etrn uses each of these
as arguments for successive ETRN commands.
The following option is supported:
-v The normal mode of operation for etrn is to do all of
its work silently. The -v option makes it verbose,
which causes etrn to display its conversations with
the remote SMTP server.
No environment variables are used. However, at system
start-up, /etc/init.d/sendmail reads /etc/default/sendmail.
In this file, if the variable ETRN_HOSTS is set,
/etc/init.d/sendmail parses this variable and invokes etrn
appropriately. ETRN_HOSTS should be of the form:
"s1:c1.1,c1.2 s2:c2.1 s3:c3.1,c3.2,c3.3"
That is, white-space separated groups of server:client where
client can be one or more comma-separated names. The :client
part is optional. server is the name of the server to prod;
a mail queue run is requested for each client name. This is
comparable to running:
/usr/lib/sendmail -qR client
on the host server.
Example 1: Using etrn
Inserting the line:
in /etc/default/sendmail results in /etc/init.d/sendmail
invoking etrn such that ETRN commands are sent to both
s1.domain.com and s2.domain.com, with both having
clnt.domain.com as the ETRN argument.
results in two ETRN commands being sent to
server.domain.com, one with the argument client1.domain.com,
the other with the argument client2.domain.com.
results in set of a ETRN commands being sent to both
server1.domain.com and server2.domain.com; each set contains
one ETRN command for each host name for which sendmail(1M)
accepts email, with that host name as the argument.
sendmail configuration file
Variables used by /etc/init.d/sendmail
See attributes(5) for descriptions of the following attri-
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
| Availability | SUNWsndmu |
sendmail(1M), RFC 1985.
Not all SMTP servers support ETRN.
Man(1) output converted with