I am running postfix as a SMTP front-end to my Exchange 2007 system. When Exchange goes down, email is bounced back to the sender as undeliverable.
How can I setup postfix to 'spool' email until the backend SMTP server is online? I have enclosed my main.cf, master.cf, and transport configs (at least the non-default ones). Main.cf: default_process_limit = 600 minimal_backoff_time = 60 maximal_backoff_time = 240 queue_minfree = 80000000 smtp_helo_timeout = 20s smtp_quit_timeout = 30s smtp_mail_timeout = 20s smtp_rcpt_timeout = 20s smtpd_helo_required = yes biff=no disable_vrfy_command = yes smtpd_recipient_restrictions = reject_invalid_hostname, reject_non_fqdn_sender, reject_non_fqdn_recipient, reject_unknown_sender_domain, # reject_unknown_recipient_domain, permit_mynetworks, reject_unauth_destination, reject_unauth_pipelining, check_recipient_access pcre:/usr/local/etc/postfix/recipient_checks.pcre, check_sender_access hash:/usr/local/etc/postfix/sender_checks, check_client_access hash:/usr/local/etc/postfix/client_checks, check_policy_service inet:127.0.0.1:12525, # check_policy_service inet:127.0.0.1:10023, permit smtpd_data_restrictions = reject_unauth_pipelining, permit smtpd_error_sleep_time = 5 smtpd_soft_error_limit = 5 smtpd_hard_error_limit = 10 smtpd_junk_command_limit = 10 smtpd_recipient_overshoot_limit = 100 maximal_queue_lifetime = 10d ############# # Spam Transport ############# transport_maps = hash:/usr/local/etc/postfix/transport #relay_recipient_maps = hash:/usr/local/etc/postfix/exchange_recipients Master.cf: smtp inet n - n - - smtpd -o smtpd_proxy_filter=127.0.0.1:10024 -o smtpd_proxy_timeout=200 127.0.0.1:24 unix - - - - 2 smtp -o smtp_data_done_timeout=1200 -o disable_dns_lookups=yes 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_client_restrictions= -o smtpd_helo_restrictions=permit_mynetworks -o smtpd_sender_restrictions= -o smtpd_recipient_restrictions=permit_mynetworks,reject -o mynetworks=127.0.0.0/8 -o maximal_queue_lifetime=10d -o strict_rfc821_envelopes=yes transport: ############## # Exchange Config ############## #company.com smtp:[mail.company.local] acme.net smtp:[10.10.10.50]
