ezmlm-limit - Limits traffic to list
ezmlm-limit [
-f file ][ -dDF ][
-t
secs ][
-n msgs ]
dir
ezmlm-limit is intended to limit traffic to a list in case an outside
source sends excessive messages. Traffic is limited by converting the list to
a message moderated list, or by deferring messages.
ezmlm-limit reads
dir/loopnum. If it does not
exist or contains a time stamp more than secs seconds old, it is
updated. If it exists, contains a time stamp less than
secs seconds
old, and
msgs messages or more have passed since
dir/loopnum was created, ezmlm-limit creates
dir /modpost. For lists set up with
ezmlm-store(1) this results in future messages being moderated.
As long as
dir/modpost does not exist,
ezmlm-store(1) will simply forward the message to
ezmlm-send(1).
Once
dir/modpost exists, messages will be queued for
moderation. Thus, in case of error (such as misconfigured auto
responders) subscribers are spared messages in excess of the limit.
However, no messages are lost, since the moderator(s) can (selectively)
approve queued messages.
If
dir/modpost already exists, ezmlm-limit will not
take any action.
Resetting the list requires manual removal of
dir/modpost.
Queued messages can be managed with regular moderation or approved
in bulk with ezmlm-accept(1).
ezmlm-limit is not required for normal lists, since qmail and ezmlm loop
detection prevent problems caused by regular bounces. However, it affords some
protection against malice, and severely misconfigured subscribers.
- -d
- Defer excess traffic. Excess messages are deferred and qmail will
re-deliver. As a consequence, traffic will be throttled to the maximum
allowed. Due to qmail delivery back-off, messages may not be disseminated
in the order received. If traffic is continuously above or close to the
limit, some messages may be delayed for a long time or even bounced.
- -D
- (Default.) Make the list moderated once excess traffic is detected. This
requires the list to be configured up with ezmlm-store(1) rather
than ezmlm-send(1), which is easiest done by first creating a
message moderated list, then removing
dir/modpost.
- -n msgs
- Trigger after msgs messages (default 30).
- -f file
- Instead of dir/loopnum use file as the time
stamp. This allows the use of multiple instances of ezmlm-limit for
the same list. For instance, you may allow 60 messages per hour with one
instance and 150 messages per day with another. If file is
relative, this is relative to dir.
- -F
- (Default.) Use dir/loopnum as the time stamp.
- -t secs
- Check the number of messages within period of secs seconds (default
3600 seconds).
ezmlm-accept(1), ezmlm-make(1), ezmlm-send(1), ezmlm-store(1), ezmlm(5)