We are currently migrating 60 or email domains to our ironport appliances.
We initially had migrated 55 or so of the lesser used domains when we became aware of a network configuration issue that caused us to move the domains back to our existing antispam solution.
Since moving the domains back, we have noticed a significant increase in the amount of spam being delivered to those domains that were migrated to the ironports for a week or so - to the point that we are receiving complaints from users about it.
Obviously we want to implement the ironports but has anyone else experienced this? Its as if the ironports are spam magnets! ;-)