NAME¶
filter-pause —
smtpd filter to pause on new connections
SYNOPSIS¶
filter-pause |
[ -s
seconds
] |
DESCRIPTION¶
filter-pause is a filter for
smtpd(8) which can be used to pause on new
connections before emitting the standard initial SMTP greeting. This is useful
to avoid the so called “slamming” technique used by some senders
of spam mails.
The options are as follows:
-s
seconds- Set the number of seconds to pause before
sending the initial greeting. The accepted values are within the range of
1s and 300s.
The default seconds value is 5s.
With
filter-pause enabled, smtpd simply waits
the specified amount of
seconds on each new
connection. If the remote server starts sending SMTP commands before the
greeting, the connection is rejected. Otherwise, the connection is accepted
and normally processed.
SEE ALSO¶
filter_api(3),
smtpd.conf(5),
smtpd(8)
STANDARDS¶
J. Klensin,
Simple Mail Transfer Protocol, RFC
5321, October 2008.
HISTORY¶
The first version of
filter-pause was written
in 2015.
AUTHORS¶
Joerg Jung
<
jung@openbsd.org>
