Hi Ligia,
I never used MassTransit but after a quick look on internet, it seams to be an FTP solution provided by GroupLogic.
I think that your company signed a contract with them.
In the features of MassTransit (
link), we can see that this solution "Supports standard FTP clients, automated FTP clients and FTP Servers".
If you want to upload files from backstage to MassTransit solution, you have to ask to GroupLogic your host, user name, password and maybe folder.
By reading the features, I think that a solution exists.
Good luck,
Franck