David F. Skoll wrote:
Arnt Gulbrandsen wrote:
An example, easily done with postfix: A set of good addresses are
(ir/)regularly copied from the primary mx, and the secondary replies 4xx
for other addresses. Done.
If both the primary and secondary MX servers are administered by the
same organization or by closely-cooperating organizations, this works
well. However, there are ISPs that offer "secondary MX service" to
their customers, and they are unlikely (or sometimes unable) to make
special arrangments to synchronize user lists.
We offer a special utility to our customers who subscribe to these
secondary MX services which allows them to export their user email
addresses, translations, aliases, etc, which is then sent to the
service. Some of the services even offer automated methods (i.e., like
sending a CVS file to a special email address). If I recall, some even
worked by making sure you added their own special "X-Headers" with
account information. As you can see below, this was not just a simple
dump utility but had many design considerations:
WcMakeEmail 1.1 - Create list of valid email addresses.
(c) copyright 2002 Santronics Software, Inc.
usage: wcMakeEmailList </new | /update> [options]
See wcMakeEmailList.htm for complete documentation
/new - generate complete list. new history file
/update - update mode, compare with history, create
difference update list in cvs format.
[options]
/nocvs - use with /update, create new entire list if changed
/server:computer - define remote Wildcat! server
/out:filename - output file (def: ValidEmailAddresses.ulist)
/in:filename - input file (def: ValidEmailAddresses.hlist)
/quiet - quiet mode, no screen output
/comment - add comment lines to output
[Email options]
/email:address - email output To: address
/to:address - same as /email
/from:address - set email From: address
/subj:subject - set email Subject: line
/tpl:filename - email template file
/rfc - template file rfc headers
/test - test mode: creates email.txt
Before we added our own AVS related features, these Anti-Spam/Virus
Service Bureaus were common with many of our customers.
Anyway, I think the point is that any real operation that needs this
type of service quite often do see the secondary MX "interfacing"
problems pretty quickly and thus take whatever action is necessary or
that is required.
--
HLS