You can send binary files (like programs and documents) with your e-mail. These are called attachments. You can attach files to any message that has not yet been sent.

An attachment is like a parcel and Messenger is a courier. Messenger just delivers the attachment, it isn’t responsible for opening it. To open the attachment you’ll need a copy of the program that was originally used to create it, or some other program that can open and convert the document.

Sometimes you can get by without using attachments: if you are e-mailing a memo that has no complicated formatting (like tables, indents or styles) then it is easier for you and your recipients to just copy the text from the word processing program and paste it into the body of the message. That way the memo is readable instantly without the recipients having to open another program.

To send an attachment, start with a new message. From the File menu, choose the Attach File(s)… command or click on the Attach button. An Open dialog box will appear: find the file then click Open.

You can also send attachments by dragging the file’s icon onto the Attachments pane of the Compose window. Either way, the names of the files appear in the Attachments list. You can attach as many files as you want, so long as the total size of the message and attachment does not exceed 5 megabytes.

You generally cannot open an attachment unless you have a copy of the program it was created with, so it’s advisable to include on the e-mail a note saying what the program and version is: there’s nothing more frustrating than having an attachment you cannot open for lack of knowing what program you need.

When you have finished composing your message and adding the attachments click on the Send button.