smartd configuration problem

[Robert McBroom]

Boot process f40 system stops for a long time with a problem with 
smartd. Seems to access the system drives and note that they are SMART 
capable. The following entries are in the journal

smartd[977]: Warning via /usr/libexec/smartmontools/smartdnotify to root 
produced>>

smartd[977]: No configuration file found at (null) or /etc/esmtprc

After multiple entries

smartd[977]: No configuration file found at (null) or /etc/esmtp

The files referenced are not in /etc. Don't see such files on a f39 system

What is the system looking to find and where can it be found.