1.5 Expect-100 meets 417
2. TLS
+ 2.1 IMAPS connection fails with rustls error
2.3 Unable to use PKCS12 certificate with Secure Transport
2.4 Secure Transport will not import PKCS#12 client certificates without a password
2.5 Client cert handling with Issuer DN differs between backends
2. TLS
+2.1 IMAPS connection fails with rustls error
+
+ https://github.com/curl/curl/issues/10457
+
2.3 Unable to use PKCS12 certificate with Secure Transport
See https://github.com/curl/curl/issues/5403