Dotaz: main.cf - Mám to správně? (ochrana pred SPAM)

[Tomas3]

nasel jsem navod na http://www.section6.net/wiki/index.php/Setting_up_Postfix_Spamassassin_Amavisd_Clamav

v main.cf mam nastaveno:

smtpd_client_restrictions = permit_mynetworks,
   reject_rbl_client list.dsbl.org,
   reject_rbl_client sbl.spamhaus.org,
   reject_rbl_client relays.ordb.org,
   reject_rbl_client bl.spamcop.net,
   reject_rbl_client dun.dnsrbl.net,
   permit

rad bych se zeptal, zda-li mi tato volba v postfixu udela to, ze mi nepropusti postfix zadne maily ze zakazanych IP adres lidi co mi posilaji maily, ktere jsou ulozeny napr. na spamhaus.org

nebo je to jen ochrana pred tim, aby overil mou IP kdyz odesilam neco z postfixu, jestli neni ulozena v cerne listine techto serveru? Diky za odpoved

Odpovědi

[erycek]

smtpd_client_restrictions

kdo se muze pripojit a zkusit dorucit email. RBL = blacklisting domen ze kterych odchazi spamy. Cili odmita maily z domen uvedenych na blacklistingu, je li na nem vlastni domena, tak to projde, protoze zalezi na poradi a permit_mynetworks je prvni.

[Tomas3]

Jasne, takze pokud se mi nekdo snazi odeslat na muj mail server mail z adresy ktera je pridana na blacklistu nejakych spolecnosti, ktere mam v tom scriptu napsane, tak je muj mail server odmitne, je to tak? Nebo je to spis pro ty lidi, kteri vyuzivaji muj mail server k odeslani postry na jine servery?

[em]

je to tak ja pisete. pokud vam nekdo posle mail z blacklistnute domeny, tak se v logu projevi napriklad takto:

Nov 10 10:52:26 _MUJ_SERVER_ postfix/smtpd[29881]: NOQUEUE: reject: RCPT from szkola-236.interblock.pl[85.219.198.236]: 554 Service unavailable; Client host [85.219.198.236] blocked using bl.spamcop.net; Blocked - see http://www.spamcop.net/bl.shtml?85.219.198.236; from=<_nejaky_spammer_> to=<_UZIVATEL_@_MUJ_SERVER_> proto=ESMTP helo=<_spamerova_domena_>

[em]

jeste k tomu dodam, ze se obcas stane, ze jsou blacklistnuty domeny nekterych velkych freemailu. Ja jsem se tedka setkal s tim, ze nechodily mejly z nekterych MX serveru z domeny seznam.cz a t-mobile.cz, takze jsem musel na prani davat nektere uzivatele na whitelist.

[em]

konfigurace mam nasledujici (v podstate jsem ji nekde kdysi opsal):

smtpd_recipient_restrictions =
  permit_mynetworks,
  permit_sasl_authenticated,
  reject_unknown_sender_domain,
  reject_unknown_recipient_domain,
  reject_non_fqdn_hostname,
  reject_non_fqdn_sender,
  reject_non_fqdn_recipient,
  reject_unauth_destination,
  reject_unauth_pipelining,
  reject_invalid_hostname,
  reject_rbl_client opm.blitzed.org,
  reject_rbl_client list.dsbl.org,
  reject_rbl_client bl.spamcop.net,
  reject_rbl_client sbl-xbl.spamhaus.org,
  reject_rbl_client relays.ordb.org,
  reject_rbl_client relays.mail-abuse.org,
  reject_rbl_client dialups.mail-abuse.org,
  reject_rbl_client blackholes.mail-abuse.org,
  reject_rbl_client blackholes.easynet.nl,
  reject_rbl_client dnsbl.njabl.org,
  reject_rbl_client dev.null.dk,
  reject_rbl_client sbl.spamhaus.org,
  reject_rbl_client dnsbl.ahbl.org

[Tomas3]

aha, takze to mate recipient_restriction a ne client_restriction ano??

Takze to nemam mit v client ale recipient?

da se nekde zjistit nebo vysvetlite mi tyto moznosti a podle ceho to postfix overuje?

  reject_unknown_sender_domain,
  reject_unknown_recipient_domain,
  reject_non_fqdn_hostname,
  reject_non_fqdn_sender,
  reject_non_fqdn_recipient,
  reject_unauth_destination,
  reject_unauth_pipelining,
  reject_invalid_hostname,

[em]

pokud si dobre pomatuji, tak smtpd_client_restrictions se bude tyka klientu. napriklad outloku. takze timto by prochazelo kontrolou vsechno co posilaji vasi uzivatele.

vse se v podstate doctete zde: http://www.postfix.org/uce.html

[em]

The smtpd_client_restrictions parameter restricts what clients this system accepts SMTP connections from.

The smtpd_recipient_restrictions parameter restricts what recipient addresses this system accepts in RCPT TO commands.

[Tomas3]

Jasne, takze to mam nacpat do:

smtpd_recipient_restrictions

a melo by to fungovat, zkusim to, prave me to zarazelo ze mi nikdo nic na toho client nerekl, takze jsem byl potichu ;o)

[eM]

jestli vam to pomuze, tak takovou mam konfiguraci postfixe: odesilani pres smtp mam povoleno pouze mynetworks, jinak zbylych par uzivatelu se overuje na smtp pomoci uzivatelskeho jmena a hesla (sasl) a jejich komunikace (tj. mezi klientem a serverem) probiham pres TLS (SSMTP/port 465 tusim). Uzivatele z domen mam nahazeny v Mysql - lepe se to administruje a kvoty jsou realizovany pres maildrop.

main.cf:

# See /usr/share/postfix/main.cf.dist for a commented, more complete version

smtpd_banner = $myhostname ESMTP $mail_name (Debian/GNU)
biff = no

# appending .domain is the MUA's job.
append_dot_mydomain = no

# Uncomment the next line to generate "delayed mail" warnings
#delay_warning_time = 4h

myhostname = mail._MOJE_DOMENA_.CZ
mydestination = $myhostname, localhost.$mydomain, $mydomain, _MOJE_DOMENA_.CZ
mynetworks = 127.0.0.0/8, _JEDNA_MOJE_SPECIALNI_SOUKROMA_ADRESA
mailbox_size_limit = 0
recipient_delimiter = +
virtual_mailbox_base = /var/vmail
virtual_minimum_uid = 500
virtual_mailbox_maps = mysql:/var/spool/postfix/etc/sql/vmailbox
virtual_maps = mysql:/var/spool/etc/postfix/sql/virtual
transport_maps = mysql:/var/spool/postfix/etc/sql/transport
virtual_uid_maps = static:500
virtual_gid_maps = static:500
local_recipient_maps = unix:passwd.byname $alias_maps $virtual_mailbox_maps
fallback_transport = virtual
relay_domains = $transport_maps
virtual_alias_maps = mysql:/var/spool/postfix/etc/sql/virtual
recipient_bcc_maps = mysql:/var/spool/postfix/etc/sql/recipient_bcc
mydomain = _MOJE_DOMENA_.CZ
myorigin = _MOJE_DOMENA_.CZ
content_filter = smtp-amavis:[127.0.0.1]:10024
maildrop_destination_recipient_limit = 1
maildrop_destination_concurrency_limit = 1
message_size_limit = 10240000
smtpd_enforce_tls = no
smtpd_tls_auth_only = yes
smtp_use_tls = yes
smtpd_use_tls = yes
smtpd_tls_key_file = /etc/postfix/ssl/smtpd.key
smtpd_tls_cert_file = /etc/postfix/ssl/smtpd.crt
smtpd_tls_CAfile = /etc/postfix/ssl/cacert.pem
smtpd_tls_loglevel = 1
smtpd_tls_received_header = yes
smtpd_tls_session_cache_timeout = 3600s
tls_random_source = dev:/dev/urandom
smtpd_sasl_auth_enable = yes
smtpd_sasl_local_domain = mail._MOJE_DOMENA_.CZ
broken_sasl_auth_clients = yes
smtpd_sasl_security_options = noanonymous
smtpd_helo_required = yes
disable_vrfy_command = yes
smtpd_recipient_restrictions =
  permit_mynetworks,
  permit_sasl_authenticated,
  reject_unknown_sender_domain,
  reject_unknown_recipient_domain,
  reject_non_fqdn_hostname,
  reject_non_fqdn_sender,
  reject_non_fqdn_recipient,
  reject_unauth_destination,
  reject_unauth_pipelining,
  reject_invalid_hostname,
  reject_rbl_client opm.blitzed.org,
  reject_rbl_client list.dsbl.org,
  reject_rbl_client bl.spamcop.net,
  reject_rbl_client sbl-xbl.spamhaus.org,
  reject_rbl_client relays.ordb.org,
  reject_rbl_client relays.mail-abuse.org,
  reject_rbl_client dialups.mail-abuse.org,
  reject_rbl_client blackholes.mail-abuse.org,
  reject_rbl_client blackholes.easynet.nl,
  reject_rbl_client dnsbl.njabl.org,
  reject_rbl_client dev.null.dk,
  reject_rbl_client sbl.spamhaus.org,
  reject_rbl_client dnsbl.ahbl.org

master.cf:

# DO NOT SHARE THE POSTFIX QUEUE BETWEEN MULTIPLE POSTFIX INSTANCES.
#
# ==========================================================================
# service type  private unpriv  chroot  wakeup  maxproc command + args
#               (yes)   (yes)   (yes)   (never) (100)
# ==========================================================================
smtp      inet  n       -       -       -       -       smtpd
#submission inet n      -       -       -       -       smtpd
#       -o smtpd_etrn_restrictions=reject
#628      inet  n       -       -       -       -       qmqpd
pickup    fifo  n       -       -       60      1       pickup
cleanup   unix  n       -       -       -       0       cleanup
qmgr      fifo  n       -       -       300     1       qmgr
#qmgr     fifo  n       -       -       300     1       oqmgr
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
smtp      unix  -       -       -       -       -       smtp
relay     unix  -       -       -       -       -       smtp
#       -o smtp_helo_timeout=5 -o smtp_connect_timeout=5
showq     unix  n       -       -       -       -       showq
error     unix  -       -       -       -       -       error
local     unix  -       n       n       -       -       local
virtual   unix  -       n       n       -       -       virtual
lmtp      unix  -       -       n       -       -       lmtp
anvil     unix  -       -       n       -       1       anvil
#
# Interfaces to non-Postfix software. Be sure to examine the manual
# pages of the non-Postfix software to find out what options it wants.
#
# maildrop. See the Postfix MAILDROP_README file for details.
#
maildrop  unix  -       n       n       -       -       pipe flags=DRhu user=vmail argv=/usr/bin/maildrop -w 90 -d ${recipient}
#  flags=DRhu user=vmail argv=/usr/bin/maildrop -d ${user}@${nexthop} ${extension} ${recipient} ${user} ${nexthop} ${sender}
#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 -d -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}

# only used by postfix-tls
#tlsmgr   fifo  -       -       n       300     1       tlsmgr
smtps     inet  n       -       n       -       -       smtpd -o smtpd_tls_wrappermode=yes -o smtpd_sasl_auth_enable=yes
#587      inet  n       -       n       -       -       smtpd -o smtpd_enforce_tls=yes -o smtpd_sasl_auth_enable=yes

smtp-amavis unix -      -       n       -       2       smtp  -o smtp_data_timeout=1200 -o disable_dns_lookups=yes -o smtp_send_xforward_command=yes
127.0.0.1:10025 inet n  -       n       -       -       smtpd -o content_filter= -o local_recipient_maps= -o relay_recipient_maps= -o smtpd_restriction_classe
s= -o smtpd_client_restrictions= -o smtpd_helo_restrictions= -o smtpd_sender_restrictions= -o smtpd_recipient_restrictions=permit_mynetworks,reject -o mynetwo
rks=127.0.0.0/8 -o strict_rfc821_envelopes=yes -o smtpd_error_sleep_time=0 -o smtpd_soft_error_limit=1001 -o smtpd_hard_error_limit=1000