We have a Domino mail server protected by Iron Port (v7.1.5 I think). Iron Port reports an average 96%-97% of emails are stopped by reputation filtering, and around 3% of emails are clean messages.
Is this level of spam going to impact on our bandwidth?
Are there other measures to prevent spam hitting Iron Port in the first place? Thanks.
Update1: we receive 28,000 emails a day. 27,000 of these are stopped by content filtering. 900 are clean emails.
Update2: The link speed is 1mbit, with 80gb bandwidth quota.
Update3: The sysadmin says IronPort stops the email being delivered by checking the sender. I guess this means only the header is received, which might be 1K at most, which means 27MB of rejected headers per day, which is 810MB per month, which is 1% of our quota. I think this is tolerable.
Thanks all for your help.