Setting up Exim on OpenBSD 3.x
Exim setup on OpenBSD 3.x

You may have other requirements for your site. We are only going to
explain how to compile exim so it works with Vexira.

1. Go to www.exim.org and download the newest version of exim and save it
to /usr/src. As of this writing, the latest version is 4.33

2. Untar the package and cd into the directory
tar -xzvf exim-4.33.tar.gz
cd exim-4.33

3. You will probably want to read the README file

4. Set the build configuration
Edit the file src/EDITME and set the following options:
BIN_DIRECTORY=/usr/local/exim/bin
CONFIGURE_FILE=/usr/local/exim/configuration
EXIM_USER=smmsp
SPOOL_DIRECTORY=/var/spool/exim

Comment out this option (prepend a #)
#EXIM_MONITOR=eximon.bin

 And copy the file to Local
 cp src/EDITME Local/Makefile

 5. Build and install the package
 make
 make install

 6. Create sendmail links to exim (ignore errors on the move commands)
 mv /usr/sbin/sendmail /usr/sbin/sendmail.old
 mv /usr/libexec/sendmail/sendmail /usr/libexec/sendmail/sendmail.old
 mv /usr/bin/mailq /usr/bin/mailq.old
 mv /usr/bin/newaliases /usr/bin/newaliases.old
 ln -s /usr/local/exim/bin/exim /usr/sbin/sendmail
 ln -s /usr/local/exim/bin/exim /usr/libexec/sendmail/sendmail
 ln -s /usr/local/exim/bin/exim /usr/bin/mailq
 ln -s /usr/local/exim/bin/exim /usr/bin/newaliases

 7. You may need to fix the permissions of /var/mail
 chmod 1777 /var/mail

 8. Start exim
 /usr/local/exim/bin/exim -bd

 9. Setting exim to start at boot.
 Add the following to /etc/rc.local
# Starting exim
 /usr/local/exim/bin/exim -bd

 Stop Sendmail from starting
 Add sendmail_flags="NO" to /etc/rc.conf.local

 10. Test exim