After installing postfix I started getting the error:

postdrop: warning: unable to look up public/pickup: No such file or directory.

This usually occurs when sendmail is installed and causing conflict with postfix.

To fix this you must run the following commands.

<pre>
<code class="language-***">
sudo service sendmail stop
sudo service sendmail disable ## to stop sendmail from starting with system

mkfifo /var/spool/postfix/public/pickup ## create the missing postfix directory

sudo service postfix restart

Related External Links:

- [https://wayilearn.blogspot.com/2011/11/fixing-error-postdrop-warning-unable-to.html](https://wayilearn.blogspot.com/2011/11/fixing-error-postdrop-warning-unable-to.html)