MultiPing doesn't create Mime-type messages, just plain email text.

Can you clarify on how you're seeing Mime-encoded messages?

Here is the body of an alert I just had fire (I removed some of the non-relevent headers).

<BEGINNING OF MESSAGE>
Return-Path: <pete@nessoft.com>
From: "MultiPing" <pete@nessoft.com>
Subject: MultiPing Auto-Alert!
To: pete@nessoft.com
Sender: MultiPing <pete@nessoft.com>
Date: Tue, 11 May 2004 12:45:35 -0600
X-Priority: 3
X-Library: Indy 9.00.10

A MultiPing alert has fired, for the following period:
5/11/2004 12:45:15 PM to Current

Monitoring: 216.92.151.75 www.pingplotter.com

Repeated every 1 second

Date/Time www.pingplotter.com
5/11/2004 12:45:15 PM *
5/11/2004 12:45:16 PM *
<remainder snipped - repeating of the same type of text>
<END OF MESSAGE>