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 withing 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>

Debian                                            May 15, 2015                                   FILTER-PAUSE(8)