I work at on online travel agency. At this time, we don't allow our customers to pick whether they would like to receive text or HTML messages. I would like to test sending Multipart MIME messages, but do not know how to implement. Is there any way you can provide detailed instructions on how to build and send these messages?
Susan Romandetti, Our Vacation Store
To answer your question, the Email Diva relied 100% on smart people Cullin J. Wible, co-founder and CTO, Email Data Services, and Tom Burke, president, Tower Data.
First, what is multipart MIME? Per Tom Burke, "A multipart MIME message is like a package with multiple boxes within it. In your standard HTML + text message, both types of content are sent in the email. Your email client, assuming it understands MIME format, will decide which of the boxes to open and display to you."
Cullin Wible continues, "It is up to the mail client to determine which content type to display or how to convert the content and format it for its own display (a la mobile devices). It's also important to note that there is no standard stating that a message must contain either format or that if they do, each part must contain the same content. For example, we see messages where the HTML part contains entirely different content then the text part." (Side note from the Email Diva: the story you tell with images may be significantly different than the one you tell without. Don't short-cut the text version by cutting and pasting your copy from the HTML version.)
How difficult is it to create a multipart MIME message? Tom answers: "For someone with programming skills, it is not difficult. Most programming languages have facilities for sending multipart MIME messages. Email Service Providers (ESPs) and email sending software generally provide the ability to create the most common type of multipart message. When you send using these tools, as you know, you define a text version and an HTML version, and, when it sends the email out, the software combines these into a multi-part message."
Cullin gets down to specifics: "From a technical perspective, composing a multipart message is much easier than coding HTML content itself. The main email message headers must contain a header that looks as follows:
Content-Type: multipart/alternative; boundary="----_=_NextPart_258_6857422.F4240" Then each part is simply delimited by the boundary "------_=_NextPart_258_6857422.F4240" on a single line. (note the two extra dashes in the beginning). The last boundary ends with an extra "--" such as "------_=_NextPart_258_6857422.F4240--". (The boundary string is simply a string of randomly generated characters that should not occur within the content.)"
So there you have it. Leave it to your programmers and...
The Email Diva
Send your questions or submit your e-mail for critique to Melinda Krueger, the E-mail Diva, at email@example.com. All submissions may be published; please indicate if you would like your name or company name withheld.