Is the compressed/zip facility provided with Windows X.P.Home
comparable to say Winzip or Filestream Turbozip for Speed in
E.Mailing.

The best way to test this is simply to compress the same thing into a
.zip file using each program and see which program makes the smallest
file. That will determine which will make files that email quicker.

I would suspect that most zip programs create zip files of comparable
size when compressing the same content.

Actually if all you are looking at is speed most likely the built in
compression to zip in windows would work fine. If you are looking for
quality in reference to size of the file i would look into one of the
following.

Winzip - is of course the most popular and the best at quality and
speed

Winace - is one of the slower compressors when compressing to an .ace
archive but it will have a much smaller file usually.

Winrar - is similar to winace in performance and quality 

If you want my personal opinion I use winace because it can also
compress to the winzip format, the win .rar format, or .ace