On Sat, Aug 07, 2021 at 11:10:39AM +0100, Chris Bamford wrote: > I would like to know how Postfix handles client certificates for delivery > i.e. when it makes a remote connection to deliver email. > > Is it possible to control the certificate that is used per domain?
Wietse posted a detailed walk through for per *sender* domain client certs. The short answer is that: * Client certificates are per-transport. Multiple TLS client certs require multiple smtp/unix transports. * You can choose the transport by destination domain, and/or partition the choice of default transport by sender domain. -- VIktor.