I have just been reading a technical board topic, where a Vectorworks file would not open. There was a lot of conversation and effort devoted to the problem, with no solution. The file had been sent to the Vectorworks support person in an uncompressed way, and the email had corrupted the file. When the file was re-sent in a compressed format, the file open easily, the first time.
Now, if the file had been sent compressed, many people would have been saved the effort of trying to figure out this problem, and the original support person could have got straight onto solving the real issue.
Always compress your files before you email or upload them to a web site, they transmit more cleanly, and faster too, saving you time.