>
> So I turn to your suggestion, but I found it hard to understand.
> \

The exim docs will help with more understanding, but I'll try to explain
further what I have going on. I use a single exim4.conf whereas it looks
like you have the debian split config. Both are fine but you'll need to
put the parts in the correct files.

>> addresslist blocked_senders = wildlsearch;/etc/exim4/denylist

> I do not have the file /etc/exim4/denylist. Were you suggesting a modification
> of an acl so that the file would be created automatically?

This is an early declaration in the exim config. It defines a list of
addresses called 'blocked senders' that we use later. My example takes a
file /etc/exim4/denylist but this can be named anything you wish,
providing exim has read access to it. It takes the form:

*@example.com
bob@???
*@spam.org

So I think will be the same as the file you already have and are trying
to feed to Spamassassin? Exim does not dynamically update it so you need
to manually add blacklisted addresses to it.

>> acl_check_rcpt:
>>    deny
>>      senders = +blocked_senders
>>      message = sender envelope address $sender_address is locally denied
>> here.
>>      log_message = Blocked $sender_address on local denylist
>> ...

> >
> I do have a /etc/exim4/conf.d/acl/30_exim4-config_check_rcpt file.
>
> I look for the stanza that starts:
>

>      deny
>             senders = +blocked_senders

>
> but I don't find it.
>

That's because this is a new part of the config. Add it in to the
/etc/exim4/conf.d/acl/30_exim4-config_check_rcpt file. It tests for a
match between the sender of the current email and the 'blocked_senders'
list we previously defined. If there is a match then the email is
denied, ie not accepted. The stanza sends a message to the sender
telling them and also writes to your log to let you know. Both of these
are optional. You could initially use 'warn' instead of 'deny' to log
(in /var/log/exim4/mainlog) the messages that would have been blocked
but not actually block them in case you've got something in the setup wrong.