CSL WROTE in a previous post re blocking web-based e-mail

same here :-)
Here we couldn't get approval for blocking web based mails, but I
an Access rules that block the extensions of the stuff I don't want
user to download. This will affect both web based e-mail and standardbrowsing, but it's a possible solution...

Novell Support Connection Volunteer Sysop

What I was wondering is once an email attachment in web based mail is
are you really downloading an attachment that is say .exe or a version
has been decoded onto your machine already ?? hence would this type of

blocking you mention actually work ???