addmap()
{
    name=$1
    if [ "x$2" != "x" ]; then
	mkmap=${2:=}
    fi
    FILE=/etc/postfix/dynamicmaps.cf
    if ! grep -q "^${name}[[:space:]]" ${FILE}; then
	 echo "Adding ${name} map entry to ${FILE}"
	 echo "${name}	postfix-${name}.so	dict_${name}_open	${mkmap}" >> ${FILE}
    fi
    return 0
}
delmap()
{
    name=$1
    FILE=/etc/postfix/dynamicmaps.cf
    if grep -q "^${name}[[:space:]]" ${FILE}; then
	 echo "Removing ${name} map entry from ${FILE}"
	 sed "/^${name}[[:space:]]/d" ${FILE} > ${FILE}.$$ && \
	     cp ${FILE}.$$ ${FILE} && \
	     rm ${FILE}.$$
    fi
    return 0
}
runnewaliases() {
    db_get postfix/main_mailer_type && mailer="$RET"
    if [ "$mailer" != "No configuration" ] || [ -f /etc/postfix/main.cf ]; then
        db_fget postfix/newaliases run || true
        if ( $RET ); then
            echo "Running newaliases"
            rm -f /etc/aliases.db   # handle the roll to db2.0
            # newaliases chokes if hostname not set
            # newaliases is equivalent to postalias $(postconf -hx alias_database)
            # and in debootstrap, newaliases == /bin/true...
            if [ -z "$(postconf -hx myhostname||true)" ]; then
                cp -a main.cf main.cf.dpkg.$$
                postconf -e 'myhostname=debian'
                newaliases
                db_fset postfix/newaliases run false
                mv main.cf.dpkg.$$ main.cf
            else
                newaliases
                db_fset postfix/newaliases run false
            fi
        fi
    fi
}