4.3. Mailman's internal archiver (Pipermail) doesn't understand MIME! What can I do?
Mailman 2.0.* uses a version of Pipermail to archive messages that doesn't understand MIME. If upgrading to Mailman 2.1.* is not an option, there's not much you can do about this other than using an external archiver.
Suggested external archivers:
HyperKitty is the default archiver for Mailman 3, but can be installed 'stand-alone' as an external archiver for Mailman 2.1.x.
MHonArc is probably the most commonly used, and is certainly the most flexible and configurable of the current Open Source mail archivers.
Example MIME messages archived under MHonArc:
(these examples are no longer available)
One of the other significant advantages of MHonArc is that it properly renders and displays messages written in national charactersets. This can be particularly valuable/important for non-english lists and authors.
Converted from the Mailman FAQ Wizard
This is one of many Frequently Asked Questions.