Our Campaigns app is still relatively new and we've been working hard to add new features to make it a more robust email campaign tool. With that goal in mind, we've recently added the ability for the campaign recipients to view a copy of the email in their browser. All you have to do to enable that is to put a simple link in your email template.
<a href="{#campaign.webversion}">View in your browser</a>
When a campaign is being sent, a copy of each email for a recipient is automatically rendered and saved as a web-version. The reason that we save a copy instead of dynamically showing a page each time the web-version is visited is because with Aptuitiv Studio Campaigns you have the ability to easily include content from other apps or other sections of your website. There are times when that content might be date sensitive, so to accommodate that we save a snapshot when the email is sent.