Have you ever received an e-mail from someone you know that has an attachment that just won't open on your Mac? I'm surprised at how often this still happens. While most of the time it's the problem of a Mac living in a Windows world, mainly Office documents and Windows media files, but sometimes it's just a file that was created with a program you don't have. There are fixes out there that can solve most file incompatibilities.
A common type of attachments is video. In the Windows world, Windows Media Player is king. In the Mac World, Apple's Quicktime is king. Quicktime, as it comes from Apple, cannot play wmv/wma files (Windows Media Video or Windows Media Audio), along with some AVI files. While Microsoft, in their infinite wisdom, abandoned their media player for OS X. Thankfully, a company called Flip4Mac stepped in to take over. If you go to the Flip4Mac Web site (www.flip4mac.com) there is a link there to get a free wmv player, which surprisingly sends you to Microsoft's Web site for the download.
This software is actually an add-on that allows Apple's own Quicktime to play back the Windows formatted video or audio. Flip4Mac has other high quality Mac software that it sells, like ScreenFlow, Drive-In, WireCast, Videocue, Episode Desktop Encoding, along with other Windows Media utilities.
Another common video file you might find is DivX. The DivX video format is loosely based on Microsoft's version of MPEG4 and has its following is growing rapidly. DivX is used to create high quality video but still maintain a small file size.
To play back DivX files, you need a DivX codec ('codec' stands for 'coder-decoder'). Go to www.divx.com to get a free DivX player, which will include the necessary codec for OS X. After installation, you should be able to play back DivX files in either Quicktime or in the DivX Player program, which is not a bad video player.
DivX has come a long way. There are numerous DVD players, Philips and Samsung are two that I have used, that can play back DivX content. Another sign that DivX is here to say are the portable devices, including cell phones, which can play DivX videos.
Another commonly found attachment is the Office file. A new Mac out of the box has no way of dealing with Office files. Don't worry most PCs can't either. An Office attachment will most likely be a Word, Excel, or PowerPoint file. One way to fix this is to buy Office for Mac. This gives your Mac compatibility with Windows PCs running Office. This will run you around $130 for the Student/Teacher version to $400 for the full version.
Another is to get Apple's iWorks 08. This is not a true Office clone, but is compatible enough for most files you'll get. Apple iWorks 08 includes Pages - a nice word processor/desktop publisher, Numbers - a spreadsheet, and Keynote - an amazing presentation program, much more visually stunning than MS PowerPoint.
There is a free way to deal with MS Office documents, and it has recently been updated. Of course I'm talking about Open Office from www.openoffice.org. In its previous versions, Open Office required the X11 extensions to be loaded into OS X to work (or you could of used NeoOffice, a version of Open Office that works natively with OS X and the Aqua desktop).
Version 3.0 of Open Office has done away with the need for X11 because it is now a true native OS X program. Included in this suite are a word processor, spreadsheet, presentation, and drawing program. There are plenty of new features and improvements in Open Office 3; of note is the ability to open the new DOCX file format that was introduced in the 2007 version of Office for Windows, a problem that even hits Windows users who haven't upgraded yet.
There are plenty of other types of files that can be found as an attachment. Most of the time they will be files that are fairly universal, like jpeg photos, or mp3 sound files. As long as your operating system and web browser is up-to-date and you have these other additions mentioned above, your e-mails shouldn't give you too much trouble.