[exim] Some virii getting through?

It appears that some virii may be getting through
my Exiscan setup. The log file has the following
errors:

demime acl condition: base64 line length exceeds 76
characters

demime acl condition: base64 line contains illegal
character

demime acl condition: base64 line length is not a
multiple of 4 characters

The emails are delivered anyway. I think this is how
the virii are getting through.

Is there a way to fix this? I am already using the
MIME
checks below:

acl_check_data:
   deny message = This message contains malformed MIME
($demime_reason).
        demime = *
        condition = ${if

>{$demime_errorlevel}{2}{1}{0}}

acl_mime:
   # Refuse Empty (invalid) MIME Boundaries
   deny condition = $mime_is_multipart
        condition = ${if
eq{$mime_boundary}{}{yes}{no}}
        message   = MIME ERROR (Empty MIME Boundary)

The examples I have seen do not list any other MIME
checks?

Thanks,

Guru


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