Sometime, either after the last patch or after our devices (Samsung EPICs) were updated to Froyo, the phones started doing this to all email replies:

REPLY TEXT<br><br>DEVICE SIGNATURE<br><br>NAME<EMAIL> wrote:<br><br>
Body of message replied to.

*It leaves the original message alone, only the text of its own reply or forward message (including signature) & the "<NAME> wrote:" parts are messed up. This happens in text & html modes. It only happens from this email account (hotmail, google, yahoo, etc. all work fine) - so it does not appear to be the Froyo mail client in general.
*It does NOT happen on initial emails, only replies & forwards.