我正在使用 check_recipient_mx_access，这样我就可以将所有 office365 托管或 google 托管的域路由到一个特殊的电子邮件网关 [因为 SPF、DMARC 等等]。
smtpd_recipient_restrictions = ..., check_recipient_mx_access hash:/etc/postfix/mx_access,...
在 /etc/postfix/mxaccess 中
.protection.outlook.com FILTER smtp:[IP.AD.DR.ESS]
.google.com FILTER smtp:[IP.AD.DR.ESS]
这对于每个收件人都很有效，但当有多个收件人时有时会失败。
例如 sender@mydom 发送到 dest1@hotmail 和 dest2@mydom2，然后 dest2@mydom2 被中继到 [IP.AD.DR.ESS]，这是错误的。
对于第一个收件人来说这是可以的，因为它的 MX 解析 something.protection.outlook.com，但对于第二个收件人来说不行，因为 mydom2 在 transport_maps 中有一个特殊的路由，在这种情况下不使用，并且因为它的 MX 不会在与 mxaccess 表匹配的东西中解析。
[如果仅 dest2@mydom2 作为收件人，则路由正常]
[如果有多个 @mydom2 @mydom3 dest，且没有匹配的 mxaccess，则路由正常]
注意：这是 ubuntu 上的 postfix 3.3.0。
postconf -M
smtp inet n - - - - smtpd
pickup fifo n - - 60 1 pickup
cleanup unix n - - - 0 cleanup
qmgr fifo n - n 300 1 qmgr
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
smtp unix - - - - - smtp
relay unix - - - - - smtp -o fallback_relay=
showq unix n - - - - showq
error 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}
retry unix - - - - - error
policyd-spf unix - n n - 0 spawn user=policyd-spf argv=/usr/sbin/postfix-policyd-spf-perl
~# postconf -n
alias_database = hash:/etc/postfix/aliases
alias_maps = hash:/etc/postfix/aliases
command_directory = /usr/sbin
compatibility_level = 2
debug_peer_level = 2
debugger_command = PATH=/usr/bin:/usr/X11R6/bin xxgdb $daemon_directory/$process_name $process_id & sleep 5
inet_interfaces = all
local_recipient_maps =
mail_owner = postfix
mailbox_command = procmail -a "$EXTENSION"
mailbox_size_limit = 0
mailq_path = /usr/bin/mailq.postfix
manpage_directory = /usr/share/man
message_size_limit = 20480000
mydestination = $myhostname, localhost.$mydomain, penty.of.domains.tld
mynetworks = 172.16.0.0/16, 192.168.10.0/24, 127.0.0.0/8, 10.0.0.0/24
myorigin = /etc/mailname
newaliases_path = /usr/bin/newaliases.postfix
queue_directory = /var/spool/postfix
readme_directory = /usr/share/doc/postfix-1.1.12/README_FILES
recipient_delimiter = +
relayhost =
sample_directory = /usr/share/doc/postfix-1.1.12/samples
sendmail_path = /usr/sbin/sendmail.postfix
setgid_group = postdrop
smtp_tls_session_cache_database = btree:${data_directory}/smtp_scache
smtpd_recipient_restrictions = reject_invalid_hostname, check_recipient_mx_access hash:/etc/postfix/mxaccess, permit_mynetworks, reject_non_fqdn_recipient, reject_unknown_recipient_domain, reject_non_fqdn_sender, check_recipient_access hash:/etc/postfix/recipientaccess, reject_unauth_pipelining, reject_unauth_destination, reject_unverified_recipient, check_sender_access hash:/etc/postfix/senderaccess, reject_unknown_sender_domain, reject_rbl_client sbl.spamhaus.org, reject_rbl_client psbl.surriel.com, reject_rbl_client bl.spamcop.net, reject_rbl_client dnsbl-3.uceprotect.net, check_policy_service inet:127.0.0.1:60000, check_policy_service unix:private/policyd-spf, permit
smtpd_relay_restrictions = reject_invalid_hostname, reject_non_fqdn_sender, reject_non_fqdn_recipient, reject_unknown_recipient_domain, permit_mynetworks, reject_unknown_sender_domain, reject_unauth_pipelining, reject_unauth_destination, check_recipient_access hash:/etc/postfix/recipientaccess, reject_unverified_recipient, check_sender_access hash:/etc/postfix/senderaccess, reject_rbl_client sbl.spamhaus.org, reject_rbl_client psbl.surriel.com, reject_rbl_client bl.spamcop.net, reject_rbl_client dnsbl-3.uceprotect.net, check_policy_service inet:127.0.0.1:60000, check_policy_service unix:private/policyd-spf, permit
smtpd_tls_cert_file = /etc/letsencrypt/live/XXXXXXXXXXXXXXX/fullchain.pem
smtpd_tls_ciphers = high
smtpd_tls_key_file = /etc/letsencrypt/live/XXXXXXXXXXXXXXX/privkey.pem
smtpd_tls_loglevel = 1
smtpd_tls_protocols = !SSLv2, !SSLv3
smtpd_tls_session_cache_database = btree:${data_directory}/smtpd_scache
smtpd_use_tls = yes
transport_maps = hash:/etc/postfix/transport
virtual_alias_domains = XXXXXXXXXX
virtual_alias_maps = regexp:/etc/postfix/virtual_re
答案1
对于第一个收件人来说这是可以的，因为它的 MX 解析 something.protection.outlook.com，但对于第二个收件人来说不行，因为 mydom2 在 transport_maps 中有一个特殊的路由，在这种情况下不使用，并且因为它的 MX 不会在与 mxaccess 表匹配的东西中解析。
我找到了这段文字：
- 如果一条消息触发多个过滤操作，则只有最后一个操作会生效。
- 相同的内容过滤器适用于给定邮件的所有收件人。