Well, one way would be work with your desktop support people to write a "rule" using VBA (Visual Basic for Applications - iirc) or some "add-in" for Outlook that would cause the ftp of a file from the local system to the mainframe. It may depend on which version of the software you are using on your system. Also be aware that as Microsoft changes, your process might also need to be changed.
The mainframe scheduling system could be set up to submit "the job" when that file is received. Your scheduling people should be able to help set up the definition in the schedulng system.
I am not familiar with this utility - SN07OM3. You might talk with whoever supports this and ask if there is a companion utility that "goes the other way".
Hope this helps,