Here is what I was able to come up with to solve the issue In the exim acl -> acl_check_rcpt: add these entries. Works great for wildcard domains and standard users.
accept condition = ${lookup pgsql{SELECT count(alias) \
FROM aliases WHERE \
alias = '${quote_pgsql:$local_part}' || '@' ||
'${quote_pgsql:$domain}'\
or alias = '@' || '${quote_pgsql:$domain}'}}
endpass
deny message = unknown user (dbmail)
Hope this help others cut down on the ndr nightmare.
