Logstash syslog output format

Just because *mail log* is that "Jun 14 14:27:42 mail46 postfix/smtpd[43252]: disconnect from pc1[192.168.0.7]"

And I want to send just only *mail log* like syslog message without Jun 14 10:23:07 ls09 %{host} LOGSTASH[ ]:

Now i have follow Jun 14 10:23:07 ls09 %{host} LOGSTASH[ ]: Jun 14 14:27:42 mail46 postfix/smtpd[43252]: disconnect from pc1[192.168.0.7]