We have 4 Brightmail scanners and one control center for all of them, v 9.0.2
Last few weeks, we have experienced random bogging down of one of the scanners.
When the bog down occurs, the scanners starts to process mail VERY SLOWLY, it takes hours to process a message. Also we see the messages queueing up in the Incoming and Outgoing queues.
We have to take the sick scanner completely out of production (set it up to not accept mail) and wait for queues to clear.
I have checked what's getting stuck in the bogged down Incoming and Outgoing queues and every time I find messages with large attachments (up to 30MB, yes, we allow large messages up to 30MB). And often those attachments are Zip files which contain a few Office 2007 documents, which in themselves contains all kinds of embedded docx, xlsx, and xml parts (Office 2007 files are funny like that).
I literally see in message history (in the audit logs) that the message had a page full of attachments, when in reality it had one zip with 4-5 files.
It looks like Brightmail has a problem dealing with such messages and bogs down.