The new features of MEG 7 are available at https://kc.mcafee.com/corporate/index?page=content&id=PD23532 . According to this document, one of the new features that might be interesting to you is that MEG 7.0 allows you to configure policies to analyze images and trigger actions based on the likelihood of the image being pornographic. This feature is something that you don't have today with EWS 5.5. and if your company is being target of messages with porn content its something that might help.
If that's not the case, I'd recommend you to provide the spams messages that are not being detected by EWS to McAfee so we can adjust/update our rules so future messages like that don't get scored to low in the future. Information about how to submit spam samples to McAfee are available at:
Note: Before upgrading, please see KB73275 (https://kc.mcafee.com/corporate/index?page=content&id=KB73275&actp=search&viewlo cale=en_US&searchid=1336141002597) .
Thanks for the info. I just upgraded, well actually the upgrade hosed, so I had to do a new install to MEG 7.0.1 and so far it seems to have decreased the spam. I also enabled the image scanning.