[Gmail-Users] No email showing up in new Gmail account inbox

I recently got a Gmail account. I send email to it from other email
systems (Thunderbird and Groupwise). No email shows in my web Gmail
inbox. I do not know how to get it to show up - none of it is even in
All Mail. I checked Spam and Trash nothing. It is like it is being
discarded and not posting to my Gmail account.

I have not imported contacts into the address book. I set up one
contact in the Gmail address book then sent an email to my Gmail
account under the name of the other person. It did not show up. I
have sent messages through different ISPs. Only the Gmail is different
email from Google has shown up in my inbox. Help please!