What is MIME Multipart?A multipart message combines one or more data sets into a single body. When this happens, a "multipart" content-type appears in the header of the message. Each of the individual parts of the multipart message is separated by encapsulating boundaries. Each body part consists of a header, blank line, and body area.
There are four main sub-types to the Multipart MIME type:
Mixed - A generic set of mixed parts. Mixed body parts are independent and meant to be displayed serially.Alternative - The same data appears in multiple formats. For example, many email marketers send two versions of their email newsletters, an HTML version and a plain text version. Depending on each recipient's individual email client settings, just one version will appear. Rather than sending two separate messages, one in HTML and the other in plain text, a single multipart/alternative message is sent. The user's email client displays the best one based on the settings in the software.
Parallel - Used for body parts meant to be viewed altogetherDigest - Each body part defaults to the message subtype of message/rfc822. Digests contain a collection of earlier messages. For example, if you subscribe to a group, you can opt to receive individual messages throughout the day or a single email at the end of the day containing all of the earlier messages.
Other Multipart subtypes include:Multipart/related
Multipart/encryptedIn general, most email clients are set up to automatically recognize and open MIME Multipart messages. If you have an email message file stored on your computer and would like to view it, you will need to open it from within an email client such as Microsoft Outlook, Outlook Express, or Windows Live Mail. If you do not have an email client installed on your computer, you will need to download and install one. You can get Windows Live Mail for free from Microsoft.com. It is part of Microsoft's Windows Live Essentials package.
Navigate to the file in Windows Explorer (Start > All Programs > Accessories > Windows Explorer) and right-click the MIME Multipart email file you want to view. Choose Open With. Your computer will likely recommend your installed email client. If so, double-click it and your email client will launch and load the file. If not, you will need to browse for it.
MIME Multipart Associated ApplicationsA number of applications exist for opening MIME Multipart messages. Some of the more popular email clients are listed below:
When you receive email messages from within any of these email applications, the MIME Multipart content type tells the client what the file is and how to display it. For the most part, you will not need to do anything other than to click on the subject line and view the message. Occasionally, an email client may not understand a MIME type.When this happens, you can often workaround the problem by forwarding the message to another service. For example, if you have a Gmail account, it may recognize the MIME type that your other email client had trouble with. This workaround is usually fine for the occasional error. However, if the MIME Multipart issue continues, you may need a more reliable fix.
MIME Multipart: How to Fix or OpenIf your email client continues to have troubles with MIME Multipart messages, start by checking for updates for your operating system, Web browser, and email client. As new MIME types are defined, computers and software need to be updated to understand the new standards. If that doesn't do the trick, clean your Windows registry with a reputable registry cleaner as this can sometimes solve MIME-related issues.
Below are more resources for learning about MIME Multipart messages:Microsoft Support: Frequently asked questions about MIME Multipart and content conversion in Exchange 2000 Server and Microsoft Exchange Server 2003 - A series of questions and answers addressing common problems and solutions for dealing with MIME Multipart issues. Though it primarily addresses issues with Exchange Server, it does have some good information about MIME in general.
MIME Messages - A discussion by IBM WebSphere's Information Center detailing MIME messages. This page includes information about MIME headers, content-types, parsing, special cases involving MIME multipart, secure MIME, and more.