I upgraded to the new version of Thunderbird and Kaspersky Total Security 2015 around the same time. Ever since Thunderbird just doesn't download my email while Kaspersky is active. No errors, just won't download. It sees how many messages are on the server starts downloading message 1 of xxx but just never gets passed 1 or downloads it. Then it just stops trying. The only way I can download my messages is to pause kaspersky protection, then reboot my pc. I can then download my emails before re enabling protection. I've already tried importing kaspersky certificates to thunderbird and doing a clean install of thunderbird with no luck. Please help.