[IMail Forum] Server not sending

[Admin]

Hi, I am new to this list but have been using Imail for 2 years.  In that time we have not experienced any major problems with Imail.  Now I have a wierd one.   Our Imail server, over a period of time, seems to stop sending mail outside of the server.  Local mail works fine always, but without any apparent reason I start getting bounces saying that messages could not be sent. If I reboot the server, Imail works fine for several days to a month, but eventually stops sending outgoing mail.   Has anyone heard of this or can anyone suggest wht might be going on here?   Thanks J. Michael Mc Kay