Hi,
To add to what Dennis said, it would be difficult to comment on an exact cause without looking at the logs and configuration of the appliance.
It is often indicative of "expensive message filters", a result of "High memory page swapping" could mean there is an opportunity to analyze your message filters and consider alternatives for filters that utilize a large amount of RAM such as dictionaries.
Its a good idea to check how much memory the machine has using command "ipcheck".
The most common cause is from having lots of email sitting in the delivery queue that have not been delivered. The appliance requires memory to keep track of any email that is showing up as an active recipient or is in a system quarantine. If the excess memory usage is because the machine has half a million emails sitting on it, you need to identify the cause and resolve it. Once you can get the emails delivered or deleted, the memory usages will go down, and the box will perform better.
If the high memory usage is not a result of lots of emails, it gets a bit harder to identify. The next most common reasons would be from the box running lots of large emails through, or having too many connections open that are transferring large emails. In those types of cases you may want to restrict the number of connections that the box is making by setting max inbound concurrency, or destconfig settings.
Regards,
Libin Varghese
