[Exim] exiscan question + upgrade to exim4

Hi all,

I use exiscan v2.4 (not in smtp-time) to virus check my incoming mail
with exim 3.36. Because I get too many viruses, I have disabled
notification of rcpt and admin, and turn on only sender.

The problem is, that because these mails mostly are sent by worms, the
sender addr is a fake addr. In this case, I (the admin) get a mail from
my server with various error messages that the notification could not be
sent.

Can I somehow disable this? I want that if the notification message
cannot be sent, then simply ignore the error and finish, and also, the
error's envelope address should be <> so the remote server also do not
answer.

Anyway, I am thinking to upgrade to exim4, then I could use the
exiscan-acl and check for viruses in smtp-time. The problem is, that I
have a quite custom exim.conf, and never used exim4 before. I have a
debian unstable server, and use exim and other standard packages (e.g.
mailman, ldap etc.) for:

- mail relaying
- mailman server
- virus checking (as above)
- custom virtualmail system using ldap and courier-{pop3d,ldapd}
- standard users' download with pop3s
- procmail for local mails

It seems to me that the biggest problem is my custom virtualmail system.
I have made two directors checking the addresses (one for "real" virtual
mailboxes, one for aliases), and one transport to put down the mails for
virtual accounts to the appropriate directories in maildir format. How
hard to rewrite this for exim4?

Also, how hard to configure mailman on exim4?

And an OT question: is there a generic, usable console-based LDAP
browser/editor?

Thanks:
Ferenc