How to make sure I have no sms virus?
I doubt that something like an SMS/MMS Virus exists or is "in the wild".

If this MMS was really originating from your phone, than this could only be caused by an malicious App. Now, there are two ways how any App can send/receive SMS/MMS:

By having the appropriate permissions

You can easily find out which App has requested, and since you installed it, granted, which permissions that App got granted. See this question for tools.

By exploiting the Android System

If there is an root exploit within the Android System and within the Dalvik VM, any App could use it to do anything. AFAIK as of Android 2.3.5 there are no public known exploits. Not sure what's the state in case of Android 2.1

SMS history

Editing the SMS history is not necessary. The history is part of the (stock) SMS client. If an Android App uses to API to send an SMS/MMS the history is not involved.