Hi Mats - I've managed to get a bit further. I decided to start from fresh.
I created 3 backends like so:-
ACME
active localacmeserv Address+Port: 192.168.50.10 8126 noWebServers
active THEMIS Address+Port: 192.168.50.189 80 noWebServers2
active GLAUCUS Address+Port: 192.168.50.185 80 noI created 4 Frontends :-
HTTP-Edge
Any (IPv4) 80
Any (IPv6) 80
Any (IPv4) 443
Any (IPv6) 443
Use "forwardfor" option - Ticked (Wasn't sure if this is needed or not)
WebServers
Shared Frontend option - ticked
Primary frontend - HTTP-Edge
Actions
Use Backend See below ACL1Use backend WebServers
I then cloned this frontend an setup an ACL for my second website to the Webservers2 backend. This all seems to work.
I created a final frontend for ACME like so:-
ACMEFrontend
Shared front end - ticked
Front end - HTTP-Edge
Backend points to ACME backend.
Attempt to renew Exchange 2013 SAN certificate which has
enabled mail.mydomain.co.uk standalone HTTP serverPort 8126
Enabled autodiscover.mydomain.co.uk standalone HTTP serverPort 8126
[Fri Jul 7 00:20:11 BST 2017] Standalone mode.
[Fri Jul 7 00:20:12 BST 2017] Standalone mode.
[Fri Jul 7 00:20:12 BST 2017] Multi domain='DNS:autodiscover.mydomain.co.uk'
[Fri Jul 7 00:20:12 BST 2017] Getting domain auth token for each domain
[Fri Jul 7 00:20:12 BST 2017] Getting webroot for domain='mail.mydomain.co.uk'
[Fri Jul 7 00:20:12 BST 2017] Getting new-authz for domain='mail.mydomain.co.uk'
[Fri Jul 7 00:20:28 BST 2017] The new-authz request is ok.
[Fri Jul 7 00:20:28 BST 2017] Getting webroot for domain='autodiscover.mydomain.co.uk'
[Fri Jul 7 00:20:28 BST 2017] Getting new-authz for domain='autodiscover.mydomain.co.uk'
[Fri Jul 7 00:20:30 BST 2017] The new-authz request is ok.
[Fri Jul 7 00:20:30 BST 2017] mail.mydomain.co.uk is already verified, skip http-01.
[Fri Jul 7 00:20:30 BST 2017] Verifying:autodiscover.mydomain.co.uk
[Fri Jul 7 00:20:30 BST 2017] Standalone mode server
[Fri Jul 7 00:20:36 BST 2017] autodiscover.mydomain.co.uk:Verify error:Invalid response from http://autodiscover.mydomain.co.uk/.well-known/acme-challenge/-G-QfC3FZa66VzIHB2rvanHig3CqBxJPONFSdO0QxLs
The Exchange 2013 server is running behind the firewall.
Any ideas? - This is hurting my brain!