I've had issues for a long time (multiple years) where I believed that I received an email, but when I went back to find it in Gmail, I could not.  I started a support ticket many months ago when I first discovered this issue and it was never resolved.  I could never prove that I got an email, that I didn't delete it, and that it should have been in my inbox and it was not.  I have a Blackberry linked to my Gmail (through the Gmail Blackberry app), and I have a number of emails in my Gmail view on the Blackberry that do not appear in my Gmail view through a web browser.   I do not delete emails from Gmail, so all should appear in both places.  

How can I get support for this issue?   Is this a known issue?