Guidelines for Email Attachments

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An e-mail attachment is a file that is attached to an e-mail message. For example, you may attach a graphic, a spreadsheet, or a word processing document. Sending attachments can be a good way to transfer a copy of a file if the sender and recipient have agreed on a format. This is easy if the same hardware and software are in use. However, differences in the computer platform being used (Windows, Mac, UNIX) and differences in versions of software can result in a failed message.

Tips For Sending Attachments

When you aren't sure, send "basic" attachments.

There are many types of attachments that can be sent via e-mail; however, not all e-mail systems handle attachments in the same way. If you are not sure what types of files your recipient can view, it is a good idea to use one of the following file types to send your attachment.

  • Plain text: save your file without formatting options such as bold and underline. All word processors and text editors should be able to read a plain text document.
  • RTF: Rich Text Format is a document format that is readable by most word processors. The RTF file is a plain text file representation of a formatted document. RTF includes codes that the recipient's word processor uses to recreate the formatted document.
  • PDF - Portable Document Format: is a file format that preserves all of the fonts, formatting, colors, and graphics of a document.

Specify what software and version was used to create the attachment

If you have communicated ahead of time with your recipient and know the types of files they can view, then it is fine to send a Microsoft Word file, a picture, or a spreadsheet. But, if the person you are sending the attachment to is using an older version of the software, they may not be able to view it, so it is helpful for them to know the version of the software. For example, you receive an Excel spreadsheet that was created with version 5.0, but you have Excel 4.0 installed on your computer; or you have Word 7.0 and the file was created in WordPerfect, you may need to tell your software what to convert from.

Don’t send attachments to e-mail lists

If you wish to share a file with members of a departmental e-mail list (e.g., abc staff), please do not send it as an attachment. This causes the file to be copied many times (once for each list member), which causes heavy traffic on both the network server (or user's hard drive) and e-mail server. The best way to share a file within your department is to store one copy of it in a "shared" area on the network server (\\fileserver\Shared) and refer to it in an e-mail note.

Limit the size of your attachments

When you send an attachment be aware that the recipient may have a limit to the size of the attachment they can receive. Most mail server has the maximum send and receive message size (and optional attachment) set between 8M and 25MB, usually. Keep in mind that someone's mailbox on the mail server will be prohibited from receiving messages if they exceed their maximum quota limit.

f you need to send the same document multiple times, change the name each time

adding a revision date and/or time to the filename. That way, each document name will be unique and it is easy to tell by the name, which version is the most recent. Then the older versions can be deleted.

Tips For Receiving Attachments

Do not open an attachment if you don't know what it is

Use caution when opening attachments that you weren't expecting or that you don't know the content. Many computer viruses are sent via e-mail attachments and can damage your computer. If you receive an attachment - especially a .exe or .vbs or .bat - and you aren't sure what it is, you should run your updated virus software before opening it.

Clean up your attachments regularly

It is a good idea to clean up your attachments on a regular basis (e.g., once a week, twice a week, etc.). If you don't, your hard drive, your mail server or your network server will become cluttered with old attachments and take up valuable storage area. Some e-mail programs have options to automatically delete your attachments when you delete the message - check your particular program to see if this is available.

Common Attachment Types and Extensions

Note that some of these extensions could be blocked by default from most mail clients if you try to send them via email.

  • Microsoft Word (.doc or .docx)
  • Microsoft Excel (.xls or .xlsx)
  • Microsoft Powerpoint (.ppt or .pps or .pptx)
  • Word Perfect (.wp)
  • Text only (.txt or .log)
  • Rich text format (.rtf)
  • Portable Document format (.pdf)
  • GIF Graphics (.gif)
  • JPEG Graphics (.jpg)
  • HTML Files (.htm or .html)
  • Self-extracting Archive (.sea or .zip or .exe)
  • Executable Files (Windows) (.exe (only open if you know what it is))
  • Visual Basic Script (.vbs (only open if you know what it is))