Thanks for that but I believe this is an email monitor program and
can not be used to verify whether a particular email address
exists which is what I'm looking for.
There's no way to do that reliably, as someone else has posted. The
best you could do would be to check that a MX record exists for the
domain and then test whether the MX seems to be working. (Then I
suppose you could actually send an e-mail and see whether it bounces,
but lack of a bounce does not necessarily mean there is a mailbox
there.)
I don't know of a freeware app that automagically looks up and tests
MXs, but there are online services that do. One is at
host.com is a valid domain with working MX, though it seems to have
some anti-spam rules preventing casual users (me) from connecting. If
that's not your real address, you should use something like
(e-mail address removed) rather than a valid address. The domain .invalid is
set aside for just such purposes.