Could someone explain why thunderbird creates so many processes per folder

[Gordon Messmer]

On 03/14/2015 04:17 PM, jd1008 wrote:
> $ lsof | grep Sent
> thunderbi 3165           jd   37u REG               8,19   3107745
> 62260168 /sdb3/home/jd/.thunderbird/jd1008/Mail/pop.googlemail.com/Sent.msf
> Gecko_IOT 3165 3192      jd   37u REG               8,19   3107745
> 62260168 /sdb3/home/jd/.thunderbird/jd1008/Mail/pop.googlemail.com/Sent.msf

PID is the second column.  All of the output you sent was PID 3165.  One 
process.