form your concern, I got two case
- direct download the Zipped folder
- Mail the Zipped file
for the first case: if you allow the users to download the file directly
then its taking one click action(that is too much friendly
to your users in case of usability) and you can feel the smile of
your clients or users.
for the second case: In this case users have to put there email id
, have to click the download/send button and then they have to go to there mail and then they have to find where the download link is , and then they will get the file by clicking the link.process is quit large. still these process is too much on the market to get more user/ traffic/ client. but its irritating to user to share there email.
Now a days many people are very aware to not getting spam in there mail.
So may be to share email id with your site may will be the one reason to get less traffic and user as comparison to first case.(no doubt if the user are your trusted user they will don't hesitate to share their email).
As per my knowledge base i will choose the one click download button instead of mail the ZIP file but in case of the mobile you can give a reminder option via mail service . that is a good and popular Idea now a days.