Validated digital signatures in an e-mail software application will:

A.
help detect spam.

B.
provide confidentiality.

C.
add to the workload of gateway servers.

D.
significantly reduce available bandwidth.

Explanation:
Validated electronic signatures are based on qualified certificates that are created by a certification authority
(CA), with the technical standards required to ensure the key can neither be forced nor reproduced in a
reasonable time. Such certificates are only delivered through a registration authority (RA) after a proof of
identity has been passed. Using strong signatures in e-mail traffic, nonrepudiation can be assured and a sender
can be tracked. The recipient can configure their e-mail server or client to automatically delete e-mails from
specific senders. For confidentiality issues, one must use encryption, not a signature, although both methods
can be based on qualified certificates. Without any filters directly applied on mail gateway servers to block
traffic without strong signatures, the workload will not increase. Using filters directly on a gateway server will
result in an overhead less than antivirus software imposes. Digital signatures are only a few bytes in size and
will not slash bandwidth. Even if gateway servers were to check CRLs, there is little overhead.