A mail exchange server — or MX — is a mail server responsible for accepting email messages on behalf of a domain name (wikipedia).

We require at least two different MX on different physical infrastructure for redundancy.

These MX — also incoming mail server — are responsible solely for Spam rejection and detection and for queueing up incoming Email in case the ?homeserver is unavailable.

Requirements

• server
• slapd
• qmail
• qmail-smtpd
• whitelist
• rbl
• surbl
• dkim

Setup

Cluster

Add hostname to locals on all servers on the qmail-ldap clusters.

Copy cluster locals to the new MX

Copy cluster rcpthosts to the new MX

Tsurbl

cd /service/qmail-smtpd || cat >&2

Edit instruct/0. Example:

+LOGLEVEL=15
+MAXRCPTCOUNT=20
+RCPTCHECK=
+RETURNMXCHECK=
+SANITYCHECK=
+SENDERCHECK=
+RBL=
# Tsurbl
+QMAILQUEUE=/usr/local/bin/qqtsurbl
+TSURBL=
# DKIM checking
+QQTSURBL=/var/qmail/bin/dkimqueue
+DKIMVERIFY=HIKLNRSTUV

DKIM

sudo -i

cd /opt/dkim || cat >&2
cp dkim /var/qmail/bin
cp dkimqueue /var/qmail/bin
chmod +x /var/qmail/bin/dkimqueue

exit

ToDo

• Distribution of locals file. Note, that on certain ?homeservers the locals only need include the home domains. - No - incorrect! What?
• Distribution of wldns data is not specified.