Delayed Local mail

[meric]

Hi guys how are U, am having problems with my qmail, it has been running
stable for the past 8 or so months.However, last week it started perfoming
in wierd way. My users on the mail server are not recieving their mails
infact the mail queue is growing and the deliveries are taking a long time,
yet there is nothing I have changed.
What do You think could be the problem and the solution.
Thanx
Eric.
Systems Engineer
Infocom Uganda Limited
Tel:077409672