This is the output from my forms example page (the movie survey) as delivered via a mailto action:
email=acadamen&seen=Citizen+Kane&seen=Casablanca&seen=The+Godfather&seen=Gone+
with+the+Wind&seen=Lawrence+of+Arabia&seen=The+Wizard+of+Oz&seen=The+Graduate
&seen=Schindler%27s+List&seen=Singing+in+the+Rain&add=gfII&add=tremors&add=
&add=&add=&dump=singing+in+the+rain&dump=wizard+of+oz&dump=&dump=&dump=
&dir=other&dir=woody+allen&actor=pacino&actor=otoole&actor=brando&uno=Casablanca
&outrage=Movie+title%3Asinging+in+the+rain
%0D%0AVent%3A+too+lightweight%0D%0A
(It actually looked worse than this when I received it; it was all in one line!)
This is the output from the same forms as processed by a script:
email
acadamen
seen
Citizen Kane
seen
Casablanca
seen
The Godfather
seen
Gone with the Wind
seen
Lawrence of Arabia
seen
The Wizard of Oz
seen
The Graduate
seen
Schindler's List
add
gfII
add
tremors
dump
singing in the rain
dump
wizard of oz
dir
other
dir
woody allen
actor
pacino
actor
otoole
actor
brando
uno
Casablanca
outrage
Movie title:singing in the rain
Vent:too lightweight
As you can see, output from a mailto processing is considerably harder to decipher than that from a script. Of course, if your form is brief, with just a few items of information, this would not be a problem.