If you mean the MOS Prize (£1500), then no, you can't submit by email.
In case you don't have the details - there are three ways to enter, all to be in by Friday 1st March -
Count how many times the letter 'i' appears in the finished grid then text ISPY followed by your answer, name & postcode to 65700 - cost £1 + network charge.
Call 0905 652 2172 & leave your answer & details - cost £1 + network charge.
Post completed grid (no photocopies) AND iSpy answer to
The Prize Crossword No 1893
The Mail on Sunday
PO Box 3451
Norwich
NR7 7NR