This would seem to be covered by the "key-sharing mechanisms that allow users to share files securely" function
Can anyone provide me with a link to a manual or user guide which explains how this bit of MEE works? I really don't want to have to purchase the product myself just to see how our partner should use it grin
then the answer is it's REALLY easy for them to encrypt data, completely transparent in fact. The likelihood is any data on removable media will be completely inaccessible to anyone outside their organization.
They do have the option of setting a policy to password protect certain files, but they may choose to turn that off.
for fully transparent sharing of data, you are also going to have to purchase the product and the two of you can share keys.
The summary answer, is it's as easy or difficult as they want it to be. The simplest/transparent is if you both use the same product.
They can either use the self-extracting files option within their current encryption product or get an exception to send data to you that is decrypted.
Additionally, you could try to work with their IT security area to find alternatives to transporting physical media unencrypted. They could use GPG or TrueCrypt (free encryption) or you could create a FTP or Web upload for them to push their files to you.