dnl
dnl проверка меток хостов как валидных эмиттеров в реверсной зоне
dnl
dnl Marking Mail Transfer Agents in Reverse DNS with TXT RRs
dnl http://www.ietf.org/internet-drafts/draft-stumpf-dns-mtamark-02.txt
dnl

dnl #
dnl # название метки
dnl # define(`confMTA_MARK', `perm.smtp.srv'
dnl # define(`confMTA_MARK', `_perm._smtp._srv'
dnl # define(`confMTA_MARK', `_send._smtp._srv'
dnl #

ifdef(`confMTA_MARK', `', `define(`confMTA_MARK', `perm.smtp.srv')')

	warn	set acl_m0	= ${lookup dnsdb{txt=confMTA_MARK.\
				${sg{$sender_host_address}\
				{\N(\d{1,3})\.(\d{1,3})\.(\d{1,3})\.(\d{1,3})\N}\
				{\$4.\$3.\$2.\$1}}\
				.in-addr.arpa}}
	deny	condition	= ${if eq{$acl_m0}{0}{yes}{no}}
		message		= Rejected: $sender_host_address not listed as MTA