Hello,
I have at work a Postfix infrastructure that sits between Internet and our
Exchange servers. Postfix is used for MX and SMTP roles, ensure filtering with
Amavisd/Clamav/etc.
For some time now I notice that some messages, either originating from Internet
or from internal servers are bounced when they arrive on the last hop: Exchange.
Typical Inbound email will go through:
MX (postfix 3.4.x + Amavisd-new) -> MAILGW (postfix 3.3.x) -> Exchange farm
Typical Internal email will go through:
SMTP (postfix 3.3.x + Amavisd-new) -> MAILGW (postfix 3.3.x) -> Exchange farm
Sample log:
Jun 17 12:34:20 postfix-mailgw/smtp[77347]: 57F56EB256:
to=<login@exchg.domain>, orig_to=<userpart@domain>,
relay=Exchange-VIP[Exchange-VIP]:25, delay=0.01, delays=0.01/0/0/0, dsn=5.6.7,
status=bounced (SMTPUTF8 is required, but was not offered by host
Exchange-VIP[Exchange-VIP])
The MAILGW instance uses these parameters :
$ postconf -nfc /usr/local/etc/postfix-mailgw
authorized_submit_users =
command_directory = /usr/local/sbin
compatibility_level = 2
config_directory = /usr/local/etc/postfix-mailgw
daemon_directory = /usr/local/libexec/postfix
data_directory = /var/db/postfix-mailgw
debug_peer_level = 2
debugger_command = PATH=/bin:/usr/bin:/usr/local/bin:/usr/X11R6/bin ddd
$daemon_directory/$process_name $process_id & sleep 5
empty_address_recipient = MAILER-DAEMON
header_checks = regexp:/usr/local/etc/postfix-mailgw/header_checks
html_directory = /usr/local/share/doc/postfix
inet_interfaces = all
inet_protocols = ipv4
local_recipient_maps =
local_transport = error:local mail delivery is disabled
mail_owner = postfix
mailbox_size_limit = 1000000000
mailq_path = /usr/local/bin/mailq
manpage_directory = /usr/local/man
master_service_disable =
message_size_limit = 21000000
multi_instance_enable = yes
multi_instance_name = postfix-mailgw
mydestination =
myhostname = mailgw.domain
mynetworks_style = host
myorigin = $myhostname
newaliases_path = /usr/local/bin/newaliases
parent_domain_matches_subdomains =
queue_directory = /var/spool/postfix-mailgw
readme_directory = /usr/local/share/doc/postfix
recipient_bcc_maps = hash:/usr/local/etc/postfix-mailgw/recipient_bcc
relay_domains = (many domains)
sample_directory = /usr/local/etc/postfix
sendmail_path = /usr/local/sbin/sendmail
setgid_group = maildrop
smtp_connection_cache_on_demand = no
smtp_destination_concurrency_limit = 50
smtp_destination_recipient_limit = 15
smtpd_banner = $myhostname ESMTP
smtpd_client_restrictions = check_client_access
hash:/usr/local/etc/postfix-mailgw/client_access reject
smtpd_recipient_restrictions = reject_unauth_destination
smtpd_timeout = 300
smtputf8_autodetect_classes = verify
transport_maps = hash:/usr/local/etc/postfix-mailgw/transport
unknown_local_recipient_reject_code = 450
virtual_alias_domains = hugo.domain domain
virtual_alias_maps = hash:/usr/local/etc/postfix-mailgw/virtual_alias
I'm suspecting something fishy with Amavisd, but I can totally rule out a
mis-setting on my Postfix servers.
Any help appreciated,
patpro
