local_part_prefix = bsmtp_ : mmdf_
local_part_prefix_optional
retry_use_local_part
- transport = ${local_part_prefix}local_delivery
+ transport = ${if !def:local_part_prefix {} \
+ {${if eq {bsmtp_}{$local_part_prefix} {bsmtp_}\
+ {${if eq {mmdf_}{$local_part_prefix} {mmdf_} {}}}}}}local_delivery
# ----- Transports -----