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Edit /etc/rc.conf and set

proxsmtpd_enable="YES"

to enable proxsmtpd.

To make it work with Postfix, see:
http://memberwebs.com/stef/software/proxsmtp/postfix.html

You can also specify the following make variables:

     PROXSMTP_BANNER="220 smtp.passthru"
     PROXSMTP_HELO_RSP="250 smtp.passthru"
     PROXSMTP_SMTP_EHLO_RSP="250-smtp.passthru"

to define default values (or to override the defaults).
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