Hello
I have setup Postfix in ubuntu 14 using this tutorial.
https://www.digitalocean.com/community/tutorials/how-to-install-and-setup-postfix-on-ubuntu-14-04

but I mail not deliver.
/var/log/mail.log file

Feb  4 08:39:16 droplet1 postfix/smtpd[16275]: fatal: open lock file pid/inet.smtp: cannot create file exclusively: No such file or directory

Feb  4 08:39:17 droplet1 postfix/master[11446]: warning: process /usr/lib/postfix/smtpd pid 16275 exit status 1

Feb  4 08:39:17 droplet1 postfix/master[11446]: warning: /usr/lib/postfix/smtpd: bad command startup -- throttling

Feb  4 08:40:02 droplet1 postfix/master[11446]: warning: master_wakeup_timer_event: service pickup(public/pickup): No such file or directory

Feb  4 08:40:17 droplet1 postfix/smtpd[16276]: fatal: open lock file pid/inet.smtp: cannot create file exclusively: No such file or directory

Feb  4 08:40:18 droplet1 postfix/master[11446]: warning: process /usr/lib/postfix/smtpd pid 16276 exit status 1

Feb  4 08:40:18 droplet1 postfix/master[11446]: warning: /usr/lib/postfix/smtpd: bad command startup -- throttling

Log file give same warning.

Please help me.
Thanks