If you purchased Poser 6 pre-release directly from the EF webstore, the download is with digital river.  You need your invoice number and login information to access it.

If you purchased it from Content Paradise, it should be in "My Stuff".  Now with EF, you had to d/l the software within 30 days of purchase (or in the case of the P7 release 30 days after) unless you purchased the Extended Download Serivce.  I don't know if SMS has the same policy.  All you can do is ask for a reset if you need one and find out what they say.