I am using Postfix 3.1.0 and following instructions at
http://www.postfix.org/TLS_README.html#client_smtps
<http://www.postfix.org/TLS_README.html#client_smtps>to set up for
sending some (recipient dependent) emails via smtps (whereas others go
over TLS to a different relay server). This uses the transport_maps
settings inmain.cf <http://main.cf/>, a transport file (hashed) and
special routing (relay-smtps) inmaster.cf <http://master.cf/>.
This works - when the onward smtps server accepts the emails. However in
my case this doesn't always happen - they sometimes block when we are
over quota. So when it fails, Postfix falls back using the hosts
specified inmain.cf <http://main.cf/>'s smtp_fallback_relay (*not*
relayhost, which is used for emails that don't have a match in the
transport list).
All well and good. But I find that after smtps rejection, the
fallback_relay hosts (both) always fail too with message like:
warning: TLS library problem: error:140770FC:SSL
routines:SSL23_GET_SERVER_HELLO:unknown protocol:s23_clnt.c:794:
With the effect that the email cannot be sent at all.
In short like this:
/etc/postfix/main.cf <http://main.cf/>
transport_maps = hash:/etc/postfix/transport
relayhost = [smtp.sendxxxx.net <http://smtp.sendxxxx.net/>]
smtp_fallback_relay = [relay.gradxxxx.net
<http://relay.gradxxxx.net/>] [smtp.sendxxxx.net
<http://smtp.sendxxxx.net/>]
/etc/postfix/transport and /etc/postfix/main.cf <http://main.cf/>-
as specified atTLS_README.html (above)for Postfix >= 3.0
However if I remove the initial attempt to use smtps (i.e. comment out
transport_maps and reload postfix), then relayhost and fallback_relays
work perfectly.
I've tried a raft of different settings without success. Any suggestions
gratefully received.
