Exporting your Sequence as an OMFI from Final Cut Pro:
Highlight your sequence in the Browser and click File > Export > Audio to OMF
Save the file using a short descriptive filename (keeping the ".omf" extension) to your removable firewire drive. Then upload to your FTP server (or deliver to me on the removable firewire drive or a USB flash drive).
The .omf file which is created contains all of your project audio and sequence timecode information. None of your audio mixing from Final Cut will transfer (volume changes, EQs, effects, etc) unless you select them.
OMF has an internal limit of 2 GB. This translates into ROUGHLY 6 tracks of mono, 16-bit audio, each one-hour long. (A 16-bit mono audio clip is roughly 5 MB per minute.)
If you try to export only part of a sequence to an OMF file, setting In's and Out's won't work. Using OMF always exports the entire sequence, regardless of how In's and Out's are set.
Consequently, if your OMF file threatens to be larger than 2 GB, turn off some of the Track Visibility lights on the far left of your Timeline. Only tracks who's visibility lights are lit (glowing green) will be exported. Then, export in sections, where each OMF file is, say, tracks 1 thru 6 and the second section is tracks 7 thru 12.