MBOXEmail Mailbox File
MBox file format is a generic term that represents a container for collection of electronic mail messages. The messages are stored inside the container along with their attachments. Messages from an entire folder are saved in a single database file and new messages are appended to the end of the file. Numerous applications and API provide support for MBox file format such as Apple Mail and Mozilla Thunderbird.
MHTMIME Encapsulation of Aggregate HTML
Files with MHT extension represent a web page archive format that can be created by a number of different applications. The format is known as archive format because it saves the web HTML code and associated resources in a single file. These resources include anything linked to the webpage such as images, applets, animations, audio files and so on.