Thunderbird is an Email client software system and you can work with it within the following method.
1. Open Mozilla thunderbird.

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2. within the left panel you’ll see a list of your email accounts. Double Click on “Inbox” or if its hidden, click on your email, and it’ll expand and show the inbox, the trash list. etc.

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Another choice is to right click on the e-mail and click on on “Get Messages”.

Thunderbird also automatically checks email each five to ten minutes. It also checks mail automatically when you open the program.