On Mon, Oct 17, 2022 at 05:37:47PM +0200, Gerald Galster wrote:
> >> This is very strange and I can confirm it.
> >
> > Can you test the other (working) certificate again? In Outlook set the
> > hostname as per certificate and in local hosts file in Windows force
> > IP of the destination server for this hostname. This way Outlook
> > should not complain about mismatched hostnames...
>
>
> Unfortunately I can't experiment with certificates (customer says
> this has been enough trouble).
>
> Can you check the certificates' serial numbers?
> The working one begins with 03 and the problematic one with 04.
>
> There are 37 archived certificates for this hostname, 29 begin
> with "03" and only 8 with "04".
>
> Certificates starting with "04" occur since autumn 2019.
> After that date it's sometimes "03" and sometimes "04".
This looks exceedingly unlikely to be relevant.
--
Viktor.
