One or two string in one line

Hi

How does one write a receipe that will do following thing:  Put mail
in mailbox which as a line with two string (one and two) like:

one     two

but save mail in error-folder if the line as only the first string like:

one

(string two is missing)

Space between one and two is irrelevant, as long there are on the same
line.

Thanks for your help

        - Gilles

Gilles Carmel, Ph.D.

Senior Scientist II
Genome Therapeutics Corporation
100 Beaver Street
Waltham, MA 02154
(617)-398-2322
telefax: (617)-647-3592

gilles(_dot_)carmel(_at_)genomecorp(_dot_)com