Unlike many other mail list managers, Mailman includes
built-in bounce handlers to help the list manager deal with addresses that have
delivery problems. If you run large lists with dynamic membership then
these settings may save you a lot of time in helping to weed out addresses that
The settings on this page control the
automatic bounce processing system in Mailman. If you set Mailman to
perform automatic bounce processing, here is an overview of that
When a bounce is received, Mailman will try to
extract two pieces of information from the bounce:
1. The address of the list member which has
generated the bounce.
2. The severity of the problem which caused the bounce.
The severity will be labeled either "hard" or "soft".
If the bounce was caused by a fatal error (such as "user unknown"),
the severity will be labeled "hard".
If the bounce was caused by a temporary error (such as "mailbox
full"), the severity will be labeled "soft".
If Mailman is in doubt about the cause of the bounce, the severity
will be labeled "hard".
If the address of the list member whose address
has bounced cannot be found, Mailman will either discard the bounce or
send it to the list owner (depending upon the settings you select on
Otherwise, each member is assigned a "bounce
score". Each time a bounce is caused by a particular member's e-mail
address, the bounce score for that member is increased. Hard bounces
increase the member's bounce score by 1. Soft bounces increase the
member's bounce score by 0.5. Increases to a particular member's
bounce score happen only once per day. This means that even if a
member's e-mail address causes ten "hard" bounces in one day, that
member's bounce score will only increase by 1.
If a member's bounce score exceeds the "bounce
score threshold" (set by you, below), the member's subscription is
disabled - or the member is unsubscribed - depending on your settings
below. If the subscription is disabled, the member will not receive
any posting from the list until the subscription is manually
re-enabled (either by the list administrator or the member). The
member will, however, receive occasional reminders that the
subscription has been disabled. These reminder messages will include
information about how to re-enable the subscription. You control both
the number of reminders sent to the member as well as the frequency
with which the reminders are sent.
You also set (below) the total number of
reminder messages that will be sent before Mailman permanently
unsubscribes the address from the mailing list. If you set this value
to 0, Mailman will skip the entire "disable and send reminders" period
and unsubscribe the e-mail address immediately.
An important setting below is the "number of days to store a member's
bounce score". If a member's e-mail address generates no bounces
during this "number of days", the bounce score for this member is
re-set to zero. By adjusting this value along with the bounce score
threshold, you can control how quickly bouncing members are disabled
and or unsubscribed.
|Should Mailman perform
automatic bounce processing?
to Yes if you'd like Mailman to perform automatic bounce handling.|
The recommended setting for this option is: Yes
|The maximum member bounce
score before the member's subscription is disabled. This value can be a
floating point number.
the "bounce score threshold" as described above.|
The recommended setting for this option is: 2
|The number of days after
which a member's bounce information is discarded, if no new bounces have
been received in the interim. This value must be an integer.
member's e-mail address generates no bounces during this period of time
(number of days), the member's bounce score is re-set to zero.|
The recommended setting for this option is: 30
|How many Your Membership
Is Disabled warnings a disabled member should get before their address
is removed from the mailing list. Set to 0 to immediately remove an address
from the list once their bounce score exceeds the threshold. This value must
be an integer.
member's subscription is disabled, how many reminder messages should Mailman
send to the member?|
Set this option to 0 if you
would like Mailman to unsubscribe bouncing addresses immediately.
The recommended setting for this option is: 0 or 2
|The number of days between
sending the Your Membership Is Disabled warnings. This value must
be an integer.
should the reminder messages be sent?|
recommended setting for this option is: 7
|Should Mailman send you, the
list owner, any bounce messages that failed to be detected by the bounce
Mailman cannot determine the e-mail address that is bouncing, should a copy
of the bounce be sent to the list owner?|
recommended setting for this option is: Yes
will do his absolute best to handle all of your list's bounces
automatically. However, there will be some bounces that require human
intervention. The list owner is required to provide that human assistance.
Mailing lists which generate bounces that are not acted upon violate
EsoSoft's Acceptable Use Policy. Inaction on the part of the list owner
could result in the deactivation of the mailing list.
|Should Mailman notify you,
the list owner, when bounces cause a member's subscription to be disabled?
Yes if you would like to be notified when a member's subscription is
There is no recommended setting for
this option. Either choice is fine.
|Should Mailman notify you,
the list owner, when bounces cause a member to be unsubscribed?
Yes if you would like to be notified when a member is unsubscribed by
Mailman because of bounces.|
There is no
recommended setting for this option. Either choice is fine.
Back to the
main Mailing List Support page.