A Custom Transformer retains all of its properties, so you can distribute it much like any other file.
To e-mail a custom transformer directly from Workbench, open the transformer file and choose File > Send To.
This opens a new e-mail window in your default e-mail client, with the transformer attached.
NOTE: You can also send the transformer by browsing to your default Transformers folder and attaching it directly to an e-mail message.
If you have set up a shared directory, any transformers in the Transformers folder are updated each time you start Workbench.