If your emails are appearing as "clipped" in Gmail, this is due to the limit on the size of the email imposed by Gmail.
Once an email goes beyond a certain size (102kb) Gmail will automatically truncate the message the recipient will need to click the View entire message to see the entire email. A recipient could also click the View In Browser link included at the top of the email to view an online version of the email. Bear in mind this does not effect any of the content in your email, it just effects what content is displayed by default.
Reducing the length of your email could help this not happen