Advice from my hosting service... Based on the default info in the mail light info ... "please note that the below changes to Postfix's main.cf file will break your
mail system, so I wouldn't recommend doing them ..."
User Documentation for ACS Mail Lite
Acs Mail Lite handles sending of email via sendmail or smtp and includes a
bounce management system for invalid email accounts.
When called to send a mail, the mail will either get sent immediately or placed
in an outgoing queue (changeable via parameter) which will be processed every
ACS Mail Lite uses either sendmail (you have to provide the location of the
binary as a parameter) or SMTP to send the mail. If the sending fails, the mail
will be placed in the outgoing queue again and be given another try a few
minutes later when processing the queue again.
Each email contains an X-Envelope-From adress constructed as follows:
The adress starts with "bounce" (can be changed by a parameter) followed by the
user_id, a hashkey and the package_id of the package instance that sent the
email, separated by "-". The domain name of this adress can be changed with a
The system checks every 2 minutes (configurable) in a certain maildirectory
(configurable) for newly bounced emails, so the mailsystem will have to place
every mail to an address beginning with "bounce" (or whatever the appropriate
parameter says) in that directory. The system then processes each of the bounced
emails, strips out the message_id and verifies the hashkey in the
bounce-address. After that the package-key of the package sending the original
mail is found out by using the package_id provided in the bounce adress. With
that, the system then tries to invoke a callback procedure via a service
contract if one is registered for that particular package-key. This enables each
package to deal with bouncing mails on their own - probably logging this in
special tables. ACS Mail Lite then logs the event of a bounced mail of that
Every day a procedure is run that checks if an email account has to be disabled
from receiving any more mail. This is done the following way:
* If a user received his last mail X days ago without any further bounced
mail then his bounce-record gets deleted since it can be assumed that his email
account is working again and no longer refusing emails. This value can be
changed with the parameter "MaxDaysToBounce".
* If more then Y emails were returned by a particular user then his email
account gets disabled from receiving any more mails from the system by setting
the email_bouncing_p flag to t. This value can be changed with the parameter
* To notify users that they will not receive any more mails and to tell them
how to reenable the email account in the system again, a notification email gets
sent every 7 days (configurable) up to 4 times (configurable) that contains a
link to reenable the email account.
To use this system here is a quick guide how to do it with postfix.
* Edit /etc/postfix/main.cf
o Set "recipient_delimiter" to " - "
o Set "home_mailbox" to "Maildir/"
o Make sure that /etc/postfix/aliases is hashed for the alias database
* Edit /etc/postfix/aliases. Redirect all mail to "bounce" (if you leave the
parameter as it was) to "nsadmin" (in case you only run one server).
In case of multiple services on one system, create a bounce email for each of
them (e.g. changeing "bounce" to "bounce_service1") and create a new user that
runs the aolserver process for each of them. You do not want to have service1
deal with bounces for service2.