A SMTP client that fully supports the Net::SMTP interface and the features that are part of Extended SMTP.
This incentive is to have a client that supports opportunistic and forced TLS, and at the same time it still fully supports the Net::SMTP interface, by inheritance. The current modules that support TLS either only supports force TLS or are implemented by partially mimicking the Net::SMTP interface, which will not be a drop-in replacement for Net::SMTP so as not to cause too much change in current applications.