We are currently using an outside service company as our email service provider.
Recently our email service has been going down because, apparently, our domain has been the target of dictionary attacks.
Our email service provider's explanation is as follows: "Basically we see upwards of 350,000 emails within 1/2 hour against the server". The return addresses are bogus and the current server does not have the capability to stop this".
Can anyone explain what a dictionary attack is?
Also, if we decide to bring our email 'in-house' what sort of impact will these dictionary attacks have on our Small Business Server 2003?
Finally, is there any type of software that will help to stop these attacks?