For several months now, some of the messages I get (I use the Mac Mail program) will arrive as, or turn into, hundreds/thousands of lines of code. It isn't just html code, either. Added stuff, too, like this top paragraph:

Content-type: text/html; charset=windows-1252
Content-transfer-encoding: quoted-printable

<html><head></head><body style=3D"word-wrap: break-word; =
-webkit-nbsp-mode: space; -webkit-line-break: after-white-space; ">The =
fonts work, but the logo is still missing the =
type.&nbsp;<div><br></div><div>Also, can we lose the rule surrounding =
the disclosure text?<br><div><br></div><div><img =
id=3D"9b395bcd-2ff2-445d-ac0d-23d798ade066" height=3D"436" width=3D"790" =
apple-width=3D"yes" apple-height=3D"yes" =
<div align=3D"left">
<p align=3D"left" style=3D"padding-left:0px; padding-top:0px; =

Sometimes the transformation occurs if I move mail mistakenly in the trash (which is another topic--why mail from senders in my address book ends up in trash) to my inbox.

It's really disruptive and frustrating, especially when it's work-related mail.

Does anyone know why this is happening and/or how I can stop it? Is there some mail file that's corrupting things? Is it a server problem? Even attachments turn to code.

Thanks for your help.