definitely content of the landing page, you need to put necessary information on your page to keep your visitors engaged. there is one more surprising fact for high bounce rate, if your visitor gets all the information needed, then that also could be a case of high bounce rate for your website.
Attention: "role based name" email prefixes such as support, webmaster, info, contact, forum, service, affiliate, admin, traffic, partners, marketing, etc., for our member accounts are not permitted. They are acceptable for a vendor listing, but not for the member email. This is due to bulk email processors scrubbing them for delivery due to extremely high bounce rates. Please apply for membership using a personalized email prefix. Something like email@example.com.
If we discover you signed up with a role based name we will give you only one message to change it. After 3 days your account will be removed if the email is not changed.