Why am I unable to open an e-mail attachment?

Updated: 12/10/2023 by Computer Hope
E-mail attachment

E-mail attachments are a great way to send files, documents, photos, and short videos to other users. In some situations, however, attachments open improperly or fail to open at all. The following sections contain multiple reasons why e-mail attachments won't open, along with some proposed solutions. Read through each section in order, or if you suspect a particular issue, you can skip to the appropriate section by clicking one of the links below.


This page is for people who cannot open an e-mail attachment. If the attachment is missing or not available, see: Why can't I receive any e-mail attachments?

Unrecognized file format

One of the most common reasons users can't open an e-mail attachment is because their computer doesn't have the necessary program installed to recognize the file format. For example, if someone is sending you a PSD (Photoshop document) image file (.psd file extension), and you don't have Adobe Photoshop or another program that supports it, the image cannot be opened.

In this situation, we recommend you have the sender save the file in a different, more common format. With our image example above, good alternatives are the JPEG (.jpg or .jpeg) or PNG (.png) file types. Once the sender has selected a file format you know you can open, have them re-send the attachment.

If you're working with this file format (.psd) often, install the appropriate program or viewer so other's don't have to make an exception when sending you that type of attachment.

Below lists some common file formats sent over e-mail, their file extension, and the programs used to open them.

File type Extension Description
Document .doc or .docx Microsoft Word documents is opened with Microsoft Word, OpenOffice Writer, or Google Docs.
PDF .pdf Adobe PDF file that is opened with Adobe Acrobat or a PDF reader.
Spreadsheet .xls or .xlsx Microsoft Excel spreadsheet that is opened with Microsoft Excel, OpenOffice Calc, or Google Sheets.
Basic Image .gif, .jpg, .jpeg, .png These basic image formats are widely used and are opened and viewed by any image editor.
Compressed file .zip, .rar, .z A compressed file that must be uncompressed before the files contained in it can be viewed.
Bitmap .bmp A Windows bitmap image is primarily opened with Microsoft Paint and can be opened with many, but not all, image editors.
Movie .avi, .mov, .wmv, .mp4, .mpeg Movie files require a compatible media player program to play.
Audio .mp3 MP3 audio files are opened and listened to with nearly all media players.
Executable .exe, .com An executable file starts the installation of a program. Be cautious of any executable sent through e-mail, as this is the primary method of distributing viruses.
HTML .html, .htm HTML files are how web pages are saved. To view these, you need an HTML editor. However, if you only want to view the code, use a text editor or, to view as a web page, open the file in an Internet browser.

Bad file association or problem with program

Adobe Acrobat PDF icon

If the file format is supported, but cannot be opened, the file association is wrong program. Or, the program it's associated with may be experiencing errors or was removed. For information about how to view and change file associations, see: How to associate a file with a program in Windows.

For example, let's say you want to edit a PDF document. While most modern web browsers include a PDF viewer, this particular PDF needs a full program so you can make changes to it. Instead of trying to open the attachment directly from your e-mail client, save the attachment to your computer (e.g., save it to your desktop).

Then, right-click the file, and under Open with, choose a different program to open it. If this works and you want the program to always open this type of file, check the box Always use this app to open and click OK.

Compressed file

compressed files

If you need to send multiple items over e-mail, it's typical to combine them into a single compressed file and send that instead. If the file is a ZIP, RAR, or another compressed file format, it must be uncompressed before it can be opened. To learn how to do so, visit the page below.

Symbols in file name

Dollar sign

If someone sends you a file with a name containing symbols, such as a dollar sign ($) or a plus (+), it's very likely that it will not open. In this instance, reply to whoever sent you the attachment and ask them to rename the file properly, then send it to you again. Another option is to save the file to your computer, and when saving it, remove the symbols from the file name. Then, try to open the file.

Antivirus program preventing

If you have an antivirus protection program installed on your computer, make sure it is not causing problems with your attachments by temporarily disabling it.

Sender has an Apple computer and you have a PC

If the e-mail sender uses a Mac computer, and the files they sent were not saved in a Windows-compatible format, you may be unable to open them. Make sure the sender of the e-mail knows you're using Windows if they are sending you an attachment that is operating system specific.

Outlook add-ins

If you are using Microsoft Outlook and unable to open attachments, make sure an add-in is not causing the problem. You can disable all add-ins in Outlook by following the steps below.

  1. Open Microsoft Outlook.
  2. Click File, and click Options.
  3. In the Outlook Options window that opens, click the Add-ins option (A) in the left navigation menu.
  4. Under or next to Manage, select COM Add-ins in the drop-down list, and click the Go button (B).

Microsoft Outlook Add-ins options.

  1. In the COM Add-ins window that opens, uncheck all the add-ins in the list, and click OK.
  2. Close and re-open Microsoft Outlook to see if the issue is resolved.

Corrupt file

If none of the suggestions above helped determine or fix the problem, the attachment you received is corrupt. Reply to the e-mail asking the sender to verify the attachment works on their computer, and have them resend it.