我遇到了一个问题 :( 当我们尝试通过 SMTP 和 Postfix + Courier + Webmin 向外部域发送邮件时，在日志中我收到一条错误：
Sep 18 10:57:34 MyDomain postfix/error[26300]: 275FF1EEC9B: to=<[email protected]>, orig_to=<postmaster>, relay=none, delay=0.01, delays=0/0/0/0, dsn=4.3.0, status=deferred (mail transport unavailable)
但是当电子邮件发送到内部帐户时没有问题。
我的 main.cf 是：
#See /usr/share/postfix/main.cf.dist for a commented, more complete version
# Debian specific: Specifying a file name will cause the first
# line of that file to be used as the name. The Debian default
# is /etc/mailname.
#myorigin = /etc/mailname
smtpd_banner = $myhostname ESMTP $mail_name biff = no
# appending .domain is the MUA's job. append_dot_mydomain = no
# Uncomment the next line to generate "delayed mail" warnings
#delay_warning_time = 4h
readme_directory = /usr/share/doc/postfix
# TLS parameters smtpd_tls_cert_file = /etc/postfix/smtpd.cert smtpd_tls_key_file = /etc/postfix/smtpd.key smtpd_use_tls = no smtpd_tls_session_cache_database = btree:${data_directory}/smtpd_scache smtp_tls_session_cache_database = btree:${data_directory}/smtp_scache
# See /usr/share/doc/postfix/TLS_README.gz in the postfix-doc package for
# information on enabling SSL in the smtp client. myhostname = domain.net alias_maps = hash:/etc/aliases alias_database = hash:/etc/aliases myorigin = /etc/mailname mydestination = domain.net, localhost, localhost.localdomain mynetworks =
127.0.0.0/8 [::ffff:127.0.0.0]/104 [::1]/128 mailbox_command = mailbox_size_limit = 0 recipient_delimiter = + inet_interfaces = all inet_protocols = all smtpd_sasl_local_domain = smtpd_sasl_auth_enable
= yes broken_sasl_auth_clients = yes smtpd_sasl_authenticated_header = yes
smtpd_recipient_restrictions = permit_mynetworks check_sender_access hash:/etc/postfix/restricted_senders permit_sasl_authenticated permit_inet_interfaces reject_unauth_destination smtp_use_tls = no smtp_tls_note_starttls_offer = yes 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 home_mailbox = Maildir/
smtpd_helo_required = yes smtpd_helo_restrictions = permit_mynetworks,
permit_sasl_authenticated,
reject_unauth_pipelining,
reject_non_fqdn_sender,
reject_non_fqdn_recipient,
reject_unknown_sender_domain,
reject_unknown_recipient_domain,
reject_unauth_destination,
reject_rbl_client sbl.spamhaus.org,
reject_rbl_client blackholes.wirehub.net,
reject_rbl_client bl.spamcop.net,
permit content_filter = amavis:[127.0.0.1]:10024 receive_override_options = no_address_mappings html_directory = /usr/share/doc/postfix/html message_size_limit = 30720000 virtual_alias_maps = proxy:mysql:/etc/postfix/mysql-virtual_forwardings.cf, mysql:/etc/postfix/mysql-virtual_email2email.cf virtual_alias_domains
= virtual_mailbox_domains = proxy:mysql:/etc/postfix/mysql-virtual_domains.cf virtual_mailbox_maps
= proxy:mysql:/etc/postfix/mysql-virtual_mailboxes.cf virtual_mailbox_base = /var/vmail virtual_uid_maps = static:5000 virtual_gid_maps = static:5000 smtpd_tls_security_level = may transport_maps = proxy:mysql:/etc/postfix/mysql-virtual_transports.cf
#relay_domains = mysql:/etc/postfix/mysql-virtual_relaydomains.cf virtual_create_maildirsize = yes virtual_maildir_extended = yes virtual_mailbox_limit_inbox = yes virtual_mailbox_limit_maps = proxy:mysql:/etc/postfix/mysql-virtual_mailbox_limit_maps.cf virtual_mailbox_limit_override = yes virtual_maildir_limit_message = "The user you are trying to reach is over quota." virtual_overquota_bounce = yes proxy_read_maps = $local_recipient_maps $mydestination $virtual_alias_maps $virtual_alias_domains $virtual_mailbox_maps $virtual_mailbox_domains $relay_recipient_maps $relay_domains canonical_maps $sender_canonical_maps $recipient_canonical_maps $relocated_maps $transport_maps $mynetworks $virtual_mailbox_limit_maps
#smtpd_sender_restrictions = check_sender_access mysql:/etc/postfix/mysql-virtual_sender.cf
# smtpd_client_restrictions = check_client_access mysql:/etc/postfix/mysql-virtual_client.cf maildrop_destination_concurrency_limit = 1 maildrop_destination_recipient_limit = 1 virtual_transport = maildrop header_checks = regexp:/etc/postfix/header_checks mime_header_checks = regexp:/etc/postfix/mime_header_checks nested_header_checks = regexp:/etc/postfix/nested_header_checks body_checks = regexp:/etc/postfix/body_checks
## local ### disable_vrfy_command = yes smtpd_banner = $myhostname smtpd_client_restrictions = permit_mynetworks permit_inet_interfaces /
在 Webmin 的“SMTP 身份验证和加密”部分中，当我们尝试取消选中“拒绝发送到其他域的电子邮件”选项时，我们再次收到失败提示，日志中显示以下内容：
致命：参数“smtpd_recipient_restrictions”：指定至少一个工作实例：check_relay_domainsreject_unauth_destination拒绝延迟defer_if_permit
因此，我们尝试在 smtpd_recipient_restrictions 中添加其中一个参数（check_relay_domains rejection_unauth_destination rejection defer_if_permit），但并未解决问题。
用户可以发送电子邮件，但服务器无法投递（所有邮件都在队列中）。
这是我的master.cf：
#
# Postfix master process configuration file. For details on the format
# of the file, see the master(5) manual page (command: "man 5 master").
#
# Do not forget to execute "postfix reload" after editing this file.
#
# ==========================================================================
# service type private unpriv chroot wakeup maxproc command + args
# (yes) (yes) (yes) (never) (100)
# ==========================================================================
smtp inet n - - - - smtpd
1025 inet n - - - - smtpd
submission inet n - - - - smtpd -o smtpd_tls_security_level=encrypt -o smtpd_sasl_auth_enable=yes -o smtpd_client_restrictions=permit_sasl_authenticat$
smtps inet n - - - - smtpd -o smtpd_tls_wrappermode=yes -o smtpd_sasl_auth_enable=yes -o smtpd_client_restrictions=permit_sasl_authenticated,reject -o mi$
628 inet n - - - - qmqpd
pickup fifo n - - 60 1 pickup
-o content_filter=
-o receive_override_options=no_header_body_checks
cleanup unix n - - - 0 cleanup
qmgr fifo n - n 300 1 qmgr
qmgr fifo 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 When relaying mail as backup MX, disable fallback_relay to avoid MX loops
relay unix - - - - - smtp
-o smtp_fallback_relay=
# -o smtp_helo_timeout=5 -o smtp_connect_timeout=5
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
#
# ====================================================================
# Interfaces to non-Postfix software. Be sure to examine the manual
# pages of the non-Postfix software to find out what options it wants.
#
# Many of the following services use the Postfix pipe(8) delivery
# agent. See the pipe(8) man page for information about ${recipient}
# and other message envelope options.
# ====================================================================
#
# maildrop. See the Postfix MAILDROP_README file for details.
# Also specify in main.cf: maildrop_destination_recipient_limit=1
#
maildrop unix - n n - - pipe
# flags=DRhu user=vmail argv=/usr/bin/maildrop -w90 -d vmail ${extension} ${recipient} ${user} ${nexthop} ${sender}
flags=DRhu user=vmail argv=/usr/bin/maildrop -w90 -d ${recipient} ${extension} ${recipient} ${user} ${nexthop} ${sender}
#
# See the Postfix UUCP_README file for configuration details.
#
uucp unix - n n - - pipe
flags=Fqhu user=uucp argv=uux -r -n -z -a$sender - $nexthop!rmail ($recipient)
#
# Other external delivery methods.
#
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}
amavis unix - - n - 2 smtp
-o smtp_data_done_timeout=1200
-o smtp_send_xforward_command=yes
-o disable_dns_lookups=yes
-o max_use=20
127.0.0.1:10025 inet n - - - - smtpd
-o content_filter=
-o local_recipient_maps=
-o relay_recipient_maps=
-o smtpd_restriction_classes=
-o smtpd_delay_reject=no
-o smtpd_client_restrictions=permit_mynetworks,reject
-o smtpd_helo_restrictions=
-o smtpd_sender_restrictions=
-o smtpd_recipient_restrictions=permit_mynetworks,reject
-o smtpd_data_restrictions=reject_unauth_pipelining
-o smtpd_end_of_data_restrictions=
-o mynetworks=127.0.0.0/8
-o smtpd_error_sleep_time=0
-o smtpd_soft_error_limit=1001
-o smtpd_hard_error_limit=1000
-o smtpd_client_connection_count_limit=0
-o smtpd_client_connection_rate_limit=0
-o receive_override_options=no_header_body_checks,no_unknown_recipient_checks
-o local_header_rewrite_clients=
你能帮助我吗？提前谢谢！！！
答案1
我不知道你的实际配置中是否有拼写错误，但你可能需要将此行拆分为master.cf
smtp unix - - - - - smtp When relaying mail as backup MX, disable fallback_relay to avoid MX loops
进入
smtp unix - - - - - smtp
# When relaying mail as backup MX, disable fallback_relay to avoid MX loops