完整错误：
Dec 23 19:44:31 example.com postfix/pickup[5589]: 39332276875: uid=0 from=<fredflinstone>
Dec 23 19:44:31 example.com postfix/cleanup[5605]: 39332276875: message-id=<[email protected]>
Dec 23 19:44:31 example.com postfix/qmgr[5590]: 39332276875: from=<[email protected]>, size=300, nrcpt=1 (queue active)
Dec 23 19:44:31 example.com postfix/smtp[5607]: 39332276875: to=<[email protected]>, relay=none, delay=0.05, delays=0.03/0.01/0.01/0, dsn=5.4.4, status=bounced (Host or domain name not found. Name service error for name=localhost type=A: Host not found)
Dec 23 19:44:31 example.com postfix/cleanup[5605]: 453F3276876: message-id=<[email protected]>
Dec 23 19:44:31 example.com postfix/bounce[5608]: 39332276875: sender non-delivery notification: 453F3276876
Dec 23 19:44:31 example.com postfix/qmgr[5590]: 453F3276876: from=<>, size=2273, nrcpt=1 (queue active)
Dec 23 19:44:31 example.com postfix/qmgr[5590]: 39332276875: removed
Dec 23 19:44:31 example.com postfix/local[5609]: 453F3276876: to=<[email protected]>, orig_to=<[email protected]>, relay=local, delay=0.02, delays=0.01/0/0/0.01, dsn=2.0.0, status=sent (delivered to maildir)
Dec 23 19:44:31 example.com postfix/qmgr[5590]: 453F3276876: removed
Localhost 位于 /etc/hosts 中。可以 ping 通它。可能是 nsswitch.conf 或 host.conf？当我从 postfix 禁用 amavis 时，邮件可以正常发送。这是我的 postfix 配置：
alias_database = hash:/etc/aliases
alias_maps = hash:/etc/aliases
append_dot_mydomain = no
biff = no
compatibility_level = 2
content_filter = smtp-amavis:[localhost]:10024
home_mailbox = Maildir/
inet_interfaces = all
inet_protocols = ipv4
mailbox_size_limit = 0
mydestination = $myhostname, example.com, localhost
myhostname = example.com
mynetworks = 127.0.0.0/8 [::ffff:127.0.0.0]/104 [::1]/128
myorigin = /etc/mailname
policy-spf_time_limit = 3600s
readme_directory = no
recipient_delimiter = +
relayhost =
smtp_tls_session_cache_database = btree:${data_directory}/smtp_scache
smtpd_banner = $myhostname ESMTP $mail_name (Ubuntu)
smtpd_recipient_restrictions = , check_policy_service unix:private/policy-spf, check_policy_service unix:private/policy-spf
smtpd_relay_restrictions = permit_mynetworks permit_sasl_authenticated defer_unauth_destination
smtpd_tls_auth_only = no
smtpd_tls_session_cache_database = btree:${data_directory}/smtpd_scache
smtpd_use_tls = no
tls_random_source = dev:/dev/urandom
/etc/nsswitch.conf
hosts: files resolv [!UNAVAIL=return] mdns4_minimal [NOTFOUND=return] dns myhostname
/etc/主机.conf
order hosts,bind
multi on
/etc/hosts
127.0.0.1 localhost
10.0.7.4 localhost example.com localhost.example.com
::1 localhost ip6-localhost ip6-loopback
/etc/postfix/master.conf
smtp inet n - y - - smtpd
pickup unix n - y 60 1 pickup
cleanup unix n - y - 0 cleanup
qmgr unix n - n 300 1 qmgr
tlsmgr unix - - y 1000? 1 tlsmgr
rewrite unix - - y - - trivial-rewrite
bounce unix - - y - 0 bounce
defer unix - - y - 0 bounce
trace unix - - y - 0 bounce
verify unix - - y - 1 verify
flush unix n - y 1000? 0 flush
proxymap unix - - n - - proxymap
proxywrite unix - - n - 1 proxymap
smtp unix - - y - - smtp
relay unix - - y - - smtp
showq unix n - y - - showq
error unix - - y - - error
retry unix - - y - - error
discard unix - - y - - discard
local unix - n n - - local
virtual unix - n n - - virtual
lmtp unix - - y - - lmtp
anvil unix - - y - 1 anvil
scache unix - - y - 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}
policy-spf unix - n n - 0 spawn
user=nobody argv=/usr/bin/policyd-spf
smtp-amavis unix - - - - 2 smtp
-o smtp_data_done_timeout=1200
-o smtp_send_xforward_command=yes
-o smtp_tls_note_starttls_offer=no
127.0.0.1:10025 inet n - - - - smtpd
-o content_filter=
-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 smtpd_restriction_classes=
-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,no_milters
-o local_header_rewrite_clients=
-o smtpd_milters=
-o local_recipient_maps=
-o relay_recipient_maps=
注意内容过滤器。如果我注释掉它，邮件就可以正常发送。所以问题出在 amavis 上？新服务器上的新安装。Ubuntu 16.10
答案1
您在 中遇到错误/etc/hosts。
您已定义10.0.7.4 localhost，这是破坏 localhost 的绝佳方法。此内容不应存在，应立即删除。
答案2
将 main.cf 中的 amavisd 内容过滤器行从 localhost 更改为 127.0.0.1 解决了该问题。