Hi Marcos,
We recommend migrating to an installation running the same version. Follow the instructions to migrate SmarterMail to a different server running version 13.x. Then, perform an upgrade to version 14.x. (Please note that SmarterMail 14.x requires installation on a Windows Server 2008 R2 64-bit or higher with Microsoft .NET 4.5 Framework.)
Below are some resources to assist you with this process:
I hope this helps!
Andrea Free
SmarterTools Inc.
877-357-6278
www.smartertools.com