Delaying is produced by greylisting. You can edit the config of postgrey to delay mails only 1 minute instead of 5 minutes.
Change /etc/default/postgrey the line
Code:
POSTGREY_OPTS="--inet=127.0.0.1:60000"
to
Code:
POSTGREY_OPTS="--inet=127.0.0.1:60000 --delay=60"
To show that postgrey works fine you can run this command:
Code:
cat /var/log/mail.log | postgreyreport \
--nosingle_line --check_sender=mx,a --show_tries \
--separate_by_subnet=":===============================================================================================\n"
Maybe it solves your problem. If not, please have a look for policyd-weight here:
http://www.policyd-weight.org/
Please test first if it works with the postgrey tuning.
Best Regards
Fluser