Is Phplist email are limited?

I have total of 4256 subscribers(email) in my database but in phplist
its show total of 3095 subscribers only. i don’t know what to do .am new
to phplist. please hel me to get through this.i need your help guys!!

What version of phpList are you using please, also how long have you been using phpList?
Are these subscribers all new? Or have you been running it a while and possibly have duplicate or unconfirmed subscribers or have some deleted themselves from your list as they don’t want to receive any more mail from you? All these options make a difference to the actual number of “live” subscribers.