Had this one and found a solution so thought I would share it...

When our androids were updated to 4.3 the inbuilt app for exchange [SSL] connectivity stopped working.
Standard PC based exchange webmail still worked fine.

Through SysLog I tracked this down to to being our app enforcement policy.

Unchecking "Wujie/UltraSurf" in OTHERS did the trick.
Ho idea why this would only affect the new Android mail app but it does for us.

Not an ideal solution to allow that through for SSL email - perhaps Draytek can investigate this one further?

Cheers
Gaz

Which firmware are you referring?

There is one beta here since last week if fix your issue
http://www.forum.draytek.co.uk/viewtopic.php?f=19&t=19313&start=80#p80330
Other way the admin should notify the support