Root and install Google apps and Market, if you haven't done so already. There are easy to follow step-by-step instructions in this and other forums, tailored for this (Coby 7015) tablet.
I flashed Watery Kyros. V1.1 on my tablet; that improved it!!! Specially the TS. You can find it here and in other forums.
I use Dolphin HD, Miran (sp? ) and Skyfire browsers and have not had any trouble accessing any of my email accounts.
Read the warnings and follow the instructions carefully. Flash at your own risk!