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Postfixは不明なローカル受信者を拒否します

後方散乱に問題があります。スパマーは、サーバーでホストされている存在しないユーザー名@存在するドメインにメールを送信します。偽造された送信者アドレスにバウンスメッセージを送り返す代わりに、セッションを中止しようとしています。 require_unverified_recipientを追加しようとしましたが、うまくいかないようです。

Mailqを確認すると、MAILER_DAEMONから存在しない受信者への「ユーザーが存在しません」というスタックしたバウンスメールが多数表示されます。

これが私のpostconf-nです

append_dot_mydomain = no
biff = no
broken_sasl_auth_clients = yes
config_directory = /etc/postfix
dovecot_destination_recipient_limit = 1
inet_interfaces = all
inet_protocols = ipv4
mailbox_size_limit = 0
message_size_limit = 102400000
milter_default_action = accept
milter_protocol = 2
mydestination = localhost
myhostname = domain.com
mynetworks = 127.0.0.0/8
non_smtpd_milters = inet:localhost:8891
readme_directory = no
recipient_delimiter = +
relay_domains =
relayhost =
resolve_numeric_domain = yes
smtp_tls_session_cache_database = btree:${data_directory}/smtp_scache
smtpd_banner = $myhostname ESMTP $mail_name (Ubuntu)
smtpd_milters = inet:localhost:8891
smtpd_relay_restrictions = permit_mynetworks, permit_sasl_authenticated, reject_unauth_destination, reject_unknown_recipient_domain, reject_unverified_recipient, permit_auth_destination
smtpd_sasl_auth_enable = yes
smtpd_sasl_path = private/auth
smtpd_sasl_security_options = noanonymous
smtpd_sasl_tls_security_options = noanonymous
smtpd_sasl_type = dovecot
smtpd_tls_CAfile = /etc/ssl/certs/domain.com.chain.crt
smtpd_tls_cert_file = /etc/ssl/certs/domain.com.crt
smtpd_tls_key_file = /etc/ssl/private/domain.com.key
smtpd_tls_session_cache_database = btree:${data_directory}/smtpd_scache
smtpd_use_tls = yes
virtual_alias_domains = mysql:/etc/postfix/sqlconf/virtual_alias_domains.cf
virtual_alias_maps = mysql:/etc/postfix/sqlconf/virtual_mailbox_maps.cf
virtual_mailbox_domains = mysql:/etc/postfix/sqlconf/mydestination.cf
virtual_transport = dovecot

これはmaster.cfファイルです

smtp      inet  n       -       -       -       -       smtpd
  -o content_filter=spamassassin
  -o receive_override_options=no_header_body_checks,no_unknown_recipient_checks,no_milters
smtps     inet  n       -       -       -       -       smtpd
  -o content_filter=checkhook
  -o smtpd_tls_wrappermode=yes
  -o smtpd_sasl_auth_enable=yes
dovecot   unix  -       n       n       -       -       pipe
  flags=DRhu user=vmail:vmail argv=/usr/lib/dovecot/deliver -f ${sender} -d ${recipient}
pickup    unix  n       -       -       60      1       pickup
cleanup   unix  n       -       -       -       0       cleanup
qmgr      unix  n       -       n       300     1       qmgr
#qmgr     unix  n       -       n       300     1       oqmgr
tlsmgr    unix  -       -       -       1000?   1       tlsmgr
rewrite   unix  -       -       -       -       -       trivial-rewrite
bounce    unix  -       -       -       -       0       bounce
defer     unix  -       -       -       -       0       bounce
trace     unix  -       -       -       -       0       bounce
verify    unix  -       -       -       -       1       verify
flush     unix  n       -       -       1000?   0       flush
proxymap  unix  -       -       n       -       -       proxymap
proxywrite unix -       -       n       -       1       proxymap
smtp      unix  -       -       -       -       -       smtp
relay     unix  -       -       -       -       -       smtp
showq     unix  n       -       -       -       -       showq
error     unix  -       -       -       -       -       error
retry     unix  -       -       -       -       -       error
discard   unix  -       -       -       -       -       discard
local     unix  -       n       n       -       -       local
virtual   unix  -       n       n       -       -       virtual
lmtp      unix  -       -       -       -       -       lmtp
anvil     unix  -       -       -       -       1       anvil
scache    unix  -       -       -       -       1       scache
maildrop  unix  -       n       n       -       -       pipe
  flags=DRhu user=vmail argv=/usr/bin/maildrop -d ${recipient}
uucp      unix  -       n       n       -       -       pipe
  flags=Fqhu user=uucp argv=uux -r -n -z -a$sender - $nexthop!rmail ($recipient)
ifmail    unix  -       n       n       -       -       pipe
  flags=F user=ftn argv=/usr/lib/ifmail/ifmail -r $nexthop ($recipient)
bsmtp     unix  -       n       n       -       -       pipe
  flags=Fq. user=bsmtp argv=/usr/lib/bsmtp/bsmtp -t$nexthop -f$sender $recipient
scalemail-backend unix  -       n       n       -       2       pipe
  flags=R user=scalemail argv=/usr/lib/scalemail/bin/scalemail-store ${nexthop} ${user} ${extension}
mailman   unix  -       n       n       -       -       pipe
  flags=FR user=list argv=/usr/lib/mailman/bin/postfix-to-mailman.py
  ${nexthop} ${user}
spamassassin unix -     n       n       -       -       pipe
  user=spamfilter argv=/usr/bin/spamc -f -e /usr/sbin/sendmail -oi -f ${sender} ${recipient}
checkhook unix  -       n       n       -       -       pipe
  user=www-data argv=/etc/postfix/scripts/send ${sender} ${recipient}

無効なローカル受信者に送信しようとしたときに作成されたログを次に示します。

Jan 22 19:09:34 ip-12345 postfix/qmgr[19938]: CF96B20013B: from=<[email protected]>, size=249, nrcpt=1 (queue active)
Jan 22 19:09:35 ip-12345 postfix/pickup[19939]: 982D320013D: uid=5007 from=<[email protected]>
Jan 22 19:09:35 ip-12345 postfix/pipe[21485]: CF96B20013B: to=<[email protected]>, relay=spamassassin, delay=18, delays=16/0/0/1.2, dsn=2.0.0, status=sent (delivered via spamassassin service)                           
Jan 22 19:09:35 ip-12345 postfix/qmgr[19938]: CF96B20013B: removed
Jan 22 19:09:35 ip-12345 postfix/cleanup[21477]: 982D320013D: message-id=<[email protected]>
Jan 22 19:09:35 ip-12345 postfix/qmgr[19938]: 982D320013D: from=<[email protected]>, size=1333, nrcpt=1 (queue active)
Jan 22 19:09:35 ip-12345 dovecot: auth: Debug: master in: USER#0111#[email protected]#011service=lda
Jan 22 19:09:35 ip-12345 dovecot: auth-worker(14636): Debug: sql([email protected]): SELECT '/var/vmail/[email protected]' as home, 'vmail' as uid, 'vmail' as gid, concat('*:storage=', quota_kb) AS quota_rule, concat('*:messages=', quota_msg) AS quota_rule2 FROM users WHERE username = 'nonexistentx' AND domain = 'localdomain.com' and active=1                          
Jan 22 19:09:35 ip-12345 dovecot: auth-worker(14636): sql([email protected]): unknown user                                                  
Jan 22 19:09:35 ip-12345 dovecot: auth: Debug: userdb out: NOTFOUND#0111       
Jan 22 19:09:35 ip-12345 postfix/pipe[21400]: 982D320013D: to=<[email protected]>, relay=dovecot, delay=0.07, delays=0.05/0/0/0.02, dsn=5.1.1, status=bounced (user unknown)                                              
Jan 22 19:09:35 ip-12345 postfix/cleanup[21396]: A8B0720013C: message-id=<[email protected]>
Jan 22 19:09:35 ip-12345 postfix/bounce[21474]: 982D320013D: sender non-delivery notification: A8B0720013C                                                   
Jan 22 19:09:35 ip-12345 postfix/qmgr[19938]: A8B0720013C: from=<>, size=3394, nrcpt=1 (queue active)                                                  
Jan 22 19:09:35 ip-12345 postfix/qmgr[19938]: 982D320013D: removed      
Jan 22 19:09:35 ip-12345 postfix/smtp[21496]: A8B0720013C: to=<[email protected]>, relay=none, delay=0.03, delays=0/0.01/0.02/0, dsn=5.4.4, status=bounced (Host or domain name not found. Name service error for name=sender.ocm type=A: Host not found)                                                              
Jan 22 19:09:35 ip-12345 postfix/qmgr[19938]: A8B0720013C: removed
1
J. Doe

有効な受信者リストのないドメインを渡す方法はここに記載されています: http://www.postfix.org/postconf.5.html#relay_recipient_maps

ドメインの特定のリストでreject_unverified_recipientを使用するには、check_recipient_accessマップを使用します。

# main.cf
smtpd_recipient_restrictions =
permit_mynetworks
permit_sasl_authenticated
reject_unauth_destination
check_recipient_access hash:/etc/postfix/verify_recipients

.。

# verify_recipients
domain1.tld reject_unverified_recipient
domain2.tld reject_unverified_recipient

クレジット: http://www.textndata.com/forums/reject_unverified_recipient-timeout-188012.html

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