On Thu, Apr 18, 2013 at 04:31:41PM +0200, L.W. van Braam van Vloten wrote: > Could you please advise what would be the preferred, secure approach to > achieve this?
When you say "secure", what security mechanisms are acceptable? You could operate a TLS protected submission service that the other host can reach via suitable SASL credentials or a TLS client certificate. Or as Ralf suggests you could just allow it to relay by its IP address. IP addresses change from time to time, but key management is not a bed of roses either. -- Viktor.