Are you saying you're accumulating all messages in Inbox?

I would like to, but that is not the case.

I want to be able to access older emails received, but I do not know how to.

Accumulating messages in Inbox isn't best practice. It is recommended to keep Inbox as tidy as possible. Most likely what happened is that your Inbox file got corrupted. Anti-virus software typically is the culprit for causing corruption. Check the size of your Inbox mbox file in the file system (via Windows Explorer). Mbox files are the ones storing the email messages. The don't have a file extension. What is the size of your Inbox file? If it's rather small, or even 0 bytes, your messages are gone. You can only recover them by restoring a recent backup of your Thunderbird profile you created prior to the incident. To avoid these kind of problems in the future, below are some general recommendations wrt anti-virus software. Create an exception in your anti-virus software for the Thunderbird profile folder, so that the anti-virus real-time scanner will not scan it. http://kb.mozillazine.org/Profile_folder_-_Thunderbird Don't let your anti-virus software scan incoming and outgoing messages. Don't let your anti-virus software scan attachments. Don't let your anti-virus software intercept your secure connection to the server. Remove any add-ons your anti-virus software may have installed in Thunderbird. Keep it working. http://kb.mozillazine.org/Keep_it_working_-_Thunderbird And last but not least, backup your Thunderbird profile on a regular basis. https://support.mozilla.org/kb/profiles-where-thunderbird-stores-user-data#w_backing-up-a-profile