How to Reduce Large Attachments in Outlook

People with slow Internet connections may have to wait for gigantic email attachments to download before they can view them. While you can’t reduce the size of an Outlook attachment to zero, you can use a few tricks to make attachments smaller and more manageable. You’ll also benefit if your Internet service provider charges you based on the amount of data you send over the Web.

Image files can reach several megabytes or more if they have large dimensions or they do not exist in a compressed format. Compressed files, such as JPEG images, are smaller than bitmaps and other types of uncompressed image files. If you need to send someone a large picture as an attachment, click the message window's "File" button and put a check mark in the "Resize Large Images When I Send this Message" check box. Outlook resizes the image so that it does not exceed 1024x768 pixels.

Compression software can reduce the sizes of certain types of files significantly. Many media files, such as MP3 songs, MPEG videos, JPEG images and PNG images are already compressed so you usually won't see significant size reductions by compressing those. Microsoft Office DOCX files don't compress well either. However, you can see significant cost savings when you compress text files, such as Hypertext Markup Language code and XML files. The compression ratio can vary depending on a text file's contents and the software you use to compress the file. Some text and database files may compress up to 90 percent. You could also see size reductions of up to 50 percent when you compress a program file.

When you you'd like to compress a file, right click it in File Manager and click "Send To." Select "Compressed Zipped Folder” and File Manager creates a folder that contains a compressed version of the file. When you get ready to send your Outlook message, attach the folder you compressed. Your recipients can decompress the attachment after they receive the message. They won't need special software because File Manager can do the job.

If you and your email recipients share a network, you don't have to send them a file as an attachment using Outlook. Instead, you could post your large file in a shared or public folder that others can access. Your email message might tell them where to find the file. If you have an account at Dropbox, SkyDrive, Google Drive or a similar file sharing service, you could also store a large attachment file there and share it with anyone.