It seems that Metastorm have introduced new features for SMTP functionality in this release. It also seems that documentation around this is scant, apart from a reference (incomplete) to some new registry entries in the Admin Guide.
As seems to be the case when Metastorm add functionality the defaults change so if you are upgrading an existing system SMTP email will cease to work unless you carry out some post installation changes which do not seem to be documented. (This may not apply if you are using a library or other custom component to send email)
Those upgrading are recommended to look at the details in the Admin Guide, together with the new registry keys themselves as they include information on options not included in the guide.