sendmail -> lmtp 501 5.6.0 Data format error

When changing in a working setup sendmail.mc

From this MAILER(smtp)dnl MAILER(procmail)dnl

To this FEATURE(local_lmtp',[IPC]',`FILE /var/run/dovecot/lmtp')dnl MAILER(local)dnl

I am getting these errors '501 5.6.0 Data format error' and ' Unrecognized host name'.

What should I change in my lmtp config? Could this be related that messages are being relayed from other servers?

lmtp_address_translate = lmtp_hdr_delivery_address = final lmtp_proxy = no lmtp_rcpt_check_quota = no lmtp_save_to_detail_mailbox = no lmtp_user_concurrency_limit = 0