It can be tricky to open the file if you don't know what application supports its file type. Here is a list of common file types and the recommended applications to open them. Read on for a more detailed description of e-mail attachments.
Many documents are simply unable to be transferred in plain text via e-mail.
For example, a picture would not be able to be displayed as text. Similarly, other file types such as spreadsheets or digital audio are unsuited for plain text. When sending information that cannot be placed in the main body of an e-mail, the only option is to send the file as an attachment. For example, if sending a text document, don't send the file in Microsoft Word format. Rich Text Format is readable by almost everyone.