Configure sendmail to use cyrusv2 mailer

Makefile

@@ -33,6 +33,12 @@ all: cyrus-config imapd-config cyrus-imapd-service services
 	sudo -u cyrus cyrus-imapd-3.2.3/tools/mkimap
 	@echo "$$CYRUS_IMAPD_SERVICE" > /lib/systemd/system/cyrus-imapd.service
 	systemctl enable cyrus-imapd.service
+	if [ -f "/etc/mail/sendmail.mc" ]; then \
+	    cd /etc/mail ; \
+	    sed -i "x;/./{x;b};x;/^MAILER(/h;//idefine(\`confLOCAL_MAILER', \`cyrusv2')dnl" sendmail.mc ; \
+	    echo "MAILER(\`cyrusv2')dnl" >> sendmail.mc ; \
+	    m4 m4/cf.m4 sendmail.mc > sendmail.cf ; \
+	fi
 	rm -rf cyrus-imapd-3.2.3
 
 cyrus-config: