/usr/include/openssl/ssl.h includes the line
As a result, the SSLv2 features are not available and are not in the man file.
However, there is no equivalent for SSL3. OPENSSL_NO_SSL3 is not defined anywhere. Thus the SSLv3 functions like SSLv3_server_method should be available. However, they do not appear in the man pages and cannot be linked to. As a result, qpopper will not properly build on 11.1-RELEASE.
The interesting aspect of this is ssl.h does include the defines for the server methods if OPENSSL_NO_SSL2_METHOD or OPENSSL_NO_SSL3_METHOD is not defined. I think at least the SSLv3_server_method (and client_method) should be linkable.