[Apologies if the formatting here is a little screwy. For the moment I have to use Outlook Web Interface, which is even more problematic than the standalone Outlook client.] > > Different OpenSSL release? > yes > openssl version > OpenSSL 1.1.1c 28 May 2019 Eh, that's probably it. I have the 1.1.1c sources here but haven't built it yet, on this machine. I'll give it a try over the weekend if I get a chance. > > Difference in build configuration? > yes Nothing in your config stands out to me. I think it's some change introduced in 1.1.1c. If no one else on the list chimes in, I'll try debugging it once I have a chance. > > Configuration file difference? > which config file are you referring to? The default OpenSSL configuration file. openssl.cnf, in the directory displayed by "openssl version -d". But I can't think offhand of anything in the configuration file that I'd expect to have this sort of effect. I don't think even engines would normally have any effect on cipher-list processing this way. -- Michael Wojcik