The best way for your HTML emails to get into Gmail inboxes is to use an email service provider. You can use a free email service provider like Mailchimp for example.
If you don't want or just don't have an ESP here is what you can do:
Export the email template from Chamaileon by generating the HTML code.
You'll need to add this Chrome add-on to be able to edit HTML in Gmail.
When you compose a new message in Gmail, ''Edit HTML'' option will appear
Click on it and add the HTML code you previously exported from Chamaileon here.
Here is a video tutorial with the Chrome add-on already installed:
Click here to see the enlarged video.
Don't try to modify the code there, but rather only in Chamaileon!