smtp_pix_workaround_delay_time
10s
Certain older Cisco PIX firewalls contain a bug that
causes them to interfere with SMTP delivery when the final period
and CR/LF indicating the end of message content arrive in separate
packets. Postfix can automatically detect the problem and adjust for
it by waiting before sending the final period and CR/LF to give the
socket send buffer a chance to empty out. The smtp_pix_workaround_delay_time parameter
specifies how long Postfix waits for the socket send buffer to
empty.