+++ /dev/null
-Date: Wed, 22 Nov 2000 17:51:42 -0500 (EST)
-From: Dave C. <djc@microwave.com>
-
-Ok.. Ive come up with something which might be worth including in the
-cookbook. Credit where it is due, the idea for this came from Nigel's
-C014..
-
-I have a setup to support ETRN for a few small (ok, two) domains.
-Currently it just leaves all the mail in the exim spool, and uses the
-default exim etrn response to flush it out.
-
-I don't like that - I agree with the opinion expressed on the list that
-mail should be delivered somewhere else, and then shoved down an SMTP
-session by some other program. Ive searched far and wide for something
-suitable to do that shoving, and finally hit upon the only program I
-trust to do that, handling errors and rejections correctly - exim
-itself.
-
-Nigel's solution for 'situation where a site I MX for has a known
-outage', combined with a bit of bash scriptery, seems to form a neat
-solution. (An intermittently connected host sort of falls under the
-'known outage' category ;)
-
-Without any further fluff, here are the details. Additional comments
-appear below..
-
-Either the real (intermittently connected) destination host needs to be
-listed as the lowest MX (with the exim server as a less preferred) , or
-the exim server needs to be the lowest MX, but have a router before the
-lookuphost router which uses route_list or something appropriate to
-normally deliver mail to the dialup host. The former is probably better
-for a host which is usually connected and is only occasionally
-disconnected (since other hosts would be able to delivery directly most
-of the time, skipping an extra relay), while the latter would probably
-work better for the converse ;) This paragraph actually applies anytime
-you are using ETRN..
-
-In either case, the routers below must precede whatever router handles
-the normal direct-to-dialup-destination..
-
---
-
-smtp_etrn_command = /etc/exim/etrn_script $domain
-
-[- Content of /etc/exim/etrn_script: -]
-#!/bin/sh
-
-# Where exim lives
-EXIM=/usr/sbin/exim
-
-# Something appropriate to generate a temporary unique string
-UNIQ=`head -c100 /dev/urandom | md5sum | cut -f 1 -d" "`
-
-arg=$1
-domain=`echo $arg | sed 's/^\#//g'`
-
-if ( test -f /var/spool/etrn/${domain} ); then
- exim_lock -q /var/spool/etrn/${domain} "mv /var/spool/etrn/${domain} /tmp/etrn-bsmtp-${UNIQ}"
- ( cat /tmp/etrn-bsmtp-${UNIQ}
- echo "QUIT" ) | $EXIM -bS -oMr etrn_requeue
- rm -f /tmp/etrn-bsmtp-${UNIQ}
-fi
-
-$EXIM -R $domain
-
-# If you use smtp_etrn_serialize, the following ensures that the
-# serialize hint is removed for the argument exactly as specified by
-# the client (which might have an # prepended if they are issuing an
-# ETRN argument as required by exim's default ETRN support
-
-$EXIM -R $arg
-
-[- end of etrn_script -]
-
-[- exim transport -]
-
-bsmtp_for_etrn:
- driver=appendfile
- file=/var/spool/etrn/${domain}
- user=exim
- bsmtp=domain
- check_string = "."
- escape_string = ".."
- prefix = ""
- suffix = ""
-
-[- routers -]
-[- You probably would want to put the domains in a file or a dbm and
-[- adjused the 'domains' setting appropriately for both of these..
-
-# If any message has already been delivered to the bsmtp file,
-# this will detect the existence of the file and all messages will
-# go there, regardless of age..
-etrn_already:
- driver = domainlist
- transport = bsmtp_for_etrn
- require_files = /var/spool/etrn/${domain}
- domains = etrntest.somedomain.com
- route_list = *
-
-# If a message has been on the queue for over the specified amount of
-# time, this will catch it and drop it into the bsmtp file
-etrn_delay:
- driver = domainlist
- transport = bsmtp_for_etrn
- condition = "${if >{$message_age}{1800} {yes}{no}}"
- domains = etrntest.somedomain.com
- route_list = *
-
-[- -]
-
-Basically, this setup lets exim try to deliver to the real host for up
-to whatever time is specified in the etrn_delay router. (1800 seconds =
-30 minutes), and then delivers all waiting messages, and any further
-messages, directly to a bsmtp file.. This setup uses one big BSMTP
-file, it probably wouldnt be too complex to have it use seperate
-files..
-
-When the etrn_script runs, it locks and renames the bsmtp file, and
-reinjects the messages to exim, which (presumably) will now be able to
-deliver them. If it can't, then once they are too old they will again
-be sent off to the bsmtp file.. (If for som reason this occurs over and
-over without exim being able to deliver them, eventually the messages
-will be returned with "too many Received headers"; this is a good
-thing, since their age will never get high enough for them to be
-returned by any retry rules)
git://git.exim.org / exim-website.git / blobdiff