[exim] lowercase local_part_suffix

Hello.

I'm using dovecot's lmtp for mail delivery and need to lowercase
local_part_suffix

Router looks as follow:

dovecot:
        driver = accept
        condition = ${lookup ldap{ldap:..(mail=$local_part@$domain)}}
        transport = dovecot_lmtpd
        debug_print = "R: dovecot for $local_part@$domain"
        domains = +local_domains
        local_parts = ! root
        cannot_route_message = Unknown user
        local_part_suffix = +*
        local_part_suffix_optional
        address_data = ${lookup ldap{ldap:..(mail=$local_part@$domain)}}

is

lowercase_dovecot:
       debug_print = "R: lower case $local_part for dovecot"
       driver = redirect
       redirect_router = dovecot
       data = ${lc:${local_part}}@${domain}

enough, or I should use

lowercase_dovecot:

        driver = redirect
        condition = ${lookup ldap{ldap:..(mail=$local_part@$domain)}}
        debug_print = "R: lower case $local_part for dovecot"
        redirect_router = dovecot
        domains = +local_domains
        local_parts = ! root
        cannot_route_message = Unknown user
        local_part_suffix = +*
        local_part_suffix_optional
        data = ${lc:${original_local_part}}@${domain}
        address_data = ${lookup ldap{ldap:..(mail=$local_part@$domain)}}

or there is a more suitable way to solve this problem?

--
sergio.