Preliminary note
OpenSMTPD is a FREE implementation of the server-side SMTP protocol as defined by RFC 5321, with some additional standart extensions.
It allows ordinary machines to exchange e-mails with other systems speaking the SMTP protocol.
OpenSMTPD runs on top of the OpenBSD operating system but also has a portable version that can build and run on several systems, including:
- Linux
- FreeBSD
- NetBSD
- DragonFly
- MacOSX
For more information: http://www.opensmtpd.org/portable.html
People interested about OpenSMTPD are encouraged to subscribe to our mailing list: http://www.opensmtpd.org/list.html
and to join the IRC channel: #OpenSMTPD @ irc.freenode.net
Cheers !
How to build, configure and use Portable OpenSMTPD
Dependencies
Portable OpenSMTPD relies on: * autoconf * automake * Berkeley DB to be built with --enable-compat185 configure flag * bison (or byacc) * libevent * libtool * openssl
Get the source
git clone -b portable git://github.com/poolpOrg/OpenSMTPD.git opensmtpd
or
wget http://www.opensmtpd.org/archives/opensmtpd-portable-latest.tar.gz
tar xzvf opensmtpd-portable-latest.tar.gz
Build
cd opensmtpd*
./bootstrap # Only if you build from git sources
./configure
make
sudo make install
Special notes for FreeBSD/DragonFlyBSD/Mac OS X:
Please launch configure with special directive about libevent directory:
FreeBSD:
./configure --with-libevent-dir=/usr/local
DragonFlyBSD:
./configure --with-libevent-dir=/usr/pkg
Mac OS X:
./configure --with-libevent-dir=/opt/local
make CFLAGS="-DBIND_8_COMPAT=1"
Install
sudo make install
Configure /etc/smtpd.conf
Please have a look at the complete format description of smtpd.conf configuration file
Add OpenSMTPD users
To operate, OpenSMTPD requires at least one user, by default _smtpd; and preferably two users, by default _smtpd and _smtpq.
Using two users instead of one will increase security by a large factor so... unless you want to voluntarily reduce security or you have absolute more faith in our code than we do, by all means use two.
The instructions below assume the default users however, the configure script allows overriding these using the options: --with-privsep-user, --with-queue-user.
NetBSD, Linux (Debian, ArchLinux, ...)
mkdir /var/empty
useradd -c "SMTP Daemon" -d /var/empty -s /sbin/nologin _smtpd
useradd -c "SMTP queue user" -d /var/empty -s /sbin/nologin _smtpq
DragonFlyBSD, FreeBSD
pw useradd _smtpd -c "SMTP Daemon" -d /var/empty -s /sbin/nologin
pw useradd _smtpq -c "SMTP queue user" -d /var/empty -s /sbin/nologin
Mac OS X
First we need a group with an unused GID below 500, list the current ones used:
/usr/bin/dscl . -list /Groups PrimaryGroupID | sort -n -k2,2
Add a group - here we have picked 444:
/usr/bin/sudo /usr/bin/dscl . -create /Groups/_smtpd PrimaryGroupID 444
Then the user. Again we need an unused UID below 500, list the current ones used:
/usr/bin/dscl . -list /Users UniqueID | sort -n -k2,2
Add a user - here we have picked 444:
/usr/bin/sudo /usr/bin/dscl . -create /Users/_smtpd UniqueID 444
/usr/bin/sudo /usr/bin/dscl . -delete /Users/_smtpd AuthenticationAuthority
/usr/bin/sudo /usr/bin/dscl . -delete /Users/_smtpd PasswordPolicyOptions
/usr/bin/sudo /usr/bin/dscl . -delete /Users/_smtpd dsAttrTypeNative:KerberosKeys
/usr/bin/sudo /usr/bin/dscl . -delete /Users/_smtpd dsAttrTypeNative:ShadowHashData
/usr/bin/sudo /usr/bin/dscl . -create /Users/_smtpd RealName "SMTP Daemon"
/usr/bin/sudo /usr/bin/dscl . -create /Users/_stmpd Password "*"
/usr/bin/sudo /usr/bin/dscl . -create /Users/_smtpd PrimaryGroupID 444
/usr/bin/sudo /usr/bin/dscl . -create /Users/_smtpd NFSHomeDirectory /var/empty
/usr/bin/sudo /usr/bin/dscl . -create /Users/_smtpd UserShell /usr/bin/false
repeat for the _smtpq user.
Launch smtpd
First, kill any running sendmail/exim/qmail/postfix or other.
Then:
smtpd &
or in debug and verbose mode
smtpd -dv