Maybe someone can answer your Tourweaver question. 

Email contents: One issue we found is that email clients like MS Outlook and maybe others, filter attachment types  like .exe's.  .exe file types are blocked from the email message body.  We find that if the exe is zipped you have a better chance for the attachment to pass.. but then that means that the receiving person must unzip in order to see the contents.

By the way, there is quite a list of file types that the email software clients dislike.  This is just the top of the list when I looked in the Help for

Attachment file types blocked by Outlook

.ade
.adp
.bas
.bat
.chm
.cmd
.cpl
.crt
.exe
..........

just a thought