Question: Why is the practice of Emailing attachments using proprietary formats
(such as MS Word) discouraged?
Author: Joseph Tam
Date: Sept. 1, 2004
A proprietary format is a format for which the specification is
not published publically; in other words, a secret format.
This discouragement is not meant for situations when the recipients
are expecting a particular format, nor when the recipients are known
to be using software that uses that particular proprietary format.
It is primarily meant for people who must Email data to an audience
whose computer environment is unknown to the sender.
The reasons to not use proprietary formatted attachments are
- It hinders the dissemination of information.
The problem with proprietary formats, as opposed to open
formats such as text, HTML, PDF, etc., is that the recipients
must have access to the proprietary software to read them.
A typical example are documents created using Microsoft Office
suite of office applications.
Microsoft users tend to have a very Microsoft-centric view
of the world and lose sight of the fact that although Microsoft
dominates the office suite software market, their use is still
This is especially true at this University, which has a diverse
computing environment, with a large user base of Non-Windows users.
Users who receive a proprietary formatted attachment are forced to
- throw the attachments away; or
- hunt down a computer with software that will allow them to read it; or
- convert it to another format that they can read; or
- buy software at someone's expense to process it.
Sometimes having the software is not enough: it may be a
different version or have resource limitations that prevents
If possible, please convert proprietary formatted data to open
formats before distribution. Furthermore, when choosing among
open formats, choose the simplest format which will convey the
information: plain text is always a good choice if suitable.
- It contributes to Email bloating.
I think most people have had the experience of getting a
large Email attachment, go through the bother of processing it
only to see a one page (or one line!) writeup formatted in such
a way as to maximize its size. It may be a scanned image of a
printed page, or more benignly, a MS-Word formatted memo.
What was sent as a 20K, 200K, or 2000K monster had no more
information than the original 20 character text. Proprietary
formats contain overhead information (such as layout, formatting
such as font choice or bolding, or image data of dust motes and
creases on a page) which is more about how information is
presented rather than the information itself.
If the extra information offered by the proprietary format is
not needed (i.e. not making a flyer for publishing), then just don't
use it. As stated above, use the simplest open format which conveys
the information you want. Often, this is just plain text.
The cost extends to more than just disk storage, but to
network usage, time involved in processing large amounts of
data, software costs as well as imposing the constraint that
your recipients have the expertise to use the software required
to intepret the attachment.
- Some formats could harbour malware.
Some formats can contain viruses (e.g. MS-Word macro viruses, MS-TNEF).
- Some formats contain more information than you intend to reveal.
Some formats can contain more information than you intend to
send (e.g. MS-Word, PDF). Enter the terms "redact Word document"
in a web search engine to see that this is a non-trivial exercise
with potentially embarrassing consequences.
In summary, please reconsider the use of proprietary formats when
sending Email to a wide audience. By converting it to the simplest and
most widely accessible formats, you will increase the likelihood that
your recipients can use it without a lot of fuss.