[exim] BODY=7BIT

I've been getting a LOT of errors similar to the following in my logs. I
haven't cared all that much since after some initial quick checking,
every one of the connections ended up being a spam bot that would have
been blocked by other means anyway.

2011-02-24 09:25:26 SMTP syntax error in "MAIL
FROM:<fpoole@???> SIZE=1016 BODY=7BIT"
H=r190-64-150-215.dialup.adsl.anteldata.net.uy (anteldata.net.uy)
[190.64.150.215] I=[203.211.140.242]:25 malformed address: SIZE=1016
BODY=7BIT may not follow <fpoole@???>

However, after some very quick checks, it seems that this construct is
actually valid. Each host is using EHLO so any esmtp extensions should
be available.

Is this a bug in Exim, or do I just not have it compiled to know
anything about the BODY= extension? Or am I seeing something from a
massively outdated RFC that no one cares about any more.

I haven't found a legitimate host doing this yet, but apparently some
version of the MS SMTP Connector (Exchange) use it, and if they turn up,
I'd like to accept them without error.

Right now it's a great spam indicator :P