Emails are not fetching from my mail server in osTicket

Hi All,

I have setup osTicket in production for my team to handle
customers issue via ticket. It was working fine before a week but
suddenly it stops fetching emails from my mail server. Soemtimes it fetch emails
and sometime it does not. It looks some issue , I have checked on my mail server
there is no issue. Please suggest me to resolve this issue. I want
osTicket to fetch emails in real time.