I got a sonicwall Pro300 for our network firewall security and a MS Exchange 2000 internally as our e-mail server, oddly, everything was working fine till recently, when user outside of the network trying to access their e-mail thru sonicwall, the sonicwall will almost lock down the internet access almost instantanously. From sonicwall's log report didn't have anything suspeciuos and from my e-mail server doesn't seems to have any hacker activaty either, Anyone who can help, will be greatly appreciated.. Thanks in advance...