fatrace not collecting data generated by dovecot

[ituxmx]

I'm trying to identify IO issues on the path where I have the mail files (/var/spool/vmail), a filesystem is created for this specific purpose; if i explore the path thru the terminal I can see commands like ls, cp, rm but when a new file is created by dovecot/smtp processes the information is not collected by fatrace.

Process I identify that are reading during the iowait is dovecot/lmtp

Is it possible to enable the monitoring using fatrace to identify the servers been created/read by dovecot or smtp servers? thanks in advance.