[exim] Change attached file extension

Hi.

Is it possible to change attached file extension?

E.g. depending on results of content scanning with clamav, can i change
extension of files, which it thinks are viruses?

As i understand, `acl_smtp_mime` looks like the right fit, but because
it runs before `acl_smtp_data` results of clamav scan will not be
available yet.
So, may be in `acl_smtp_data` or somewhere later? I can't find how to do
this, can you give some hints?

--
     Dmitriy