including email attachments

How to include email attachments

When sending an email message, you may want to include a document that was created separately. Some examples are a Word file that includes all the formatting information, an Excel spreadsheet, and an image file. These types of documents are non-text (binary) and cannot simply be copied into the message body. They need to be sent as attachments. Most mail packages allow you to send a document as an attachment so that none of the original formatting is lost in the transfer.

The person receiving the message:

  • must have an email program that can receive the attachment.
  • must be able to start the same application with which the original document was created.

File extensions

It is strongly recommended not to change the default file extension of a document that you are creating with an application such as Word. The file extension is the three-letter code after the period. For example, in myfile.doc, doc is the extension). The first part of the file can be anything you like. If the extension of a file that you send as an attachment is kept as the default, then the receiver can just double click on the file and the appropriate application will open with that document. If the extension was changed, the receiver may have difficulty opening the document.

Two common default extensions are .doc (for Microsoft Word) and .xls (for Microsoft Excel).

Transmission protocol (encoding)

In order for an attachment to be sent correctly via email, it needs to be converted to a format that can be sent over the Internet. You need to find out what kind of mail program the receiver is using and what kind of transmission protocols it recognizes (MIME and Binhex are two).

The sending email program will automatically transmit the document in the proper format and the receiving email will automatically convert the document back to its original form.

MIME (Multipurpose Internet Mail Extensions) is the transmission protocol used by most mail programs.