I replaced Norton with ZA on the suggestion of my ISP tech support when I had a major problem (a trojan got through Norton and totally destroyed my MS IE).
I was generally pleased with ZA, so bought ZAPro.
The problem is: With Norton, when an email contained images, Norton showed a clickable bar in the email to allow images if I so wished. ZAP doesn't; instead, it's completely blocking *all* email images. I've hunted all over in the ZAP options and canNOT find a setting to allow them.
Further, isn't there any way to (like Norton) choose among  blocking images from sender,  allowing images in one specific email, or  labeling the sender as a "safe sender" and permanently allowing all images he sends?
MS Office Outlook 2003 v11.8010.8036 SP2
FireFox: Mozilla/5.0 Gecko/20060909 Firefox/22.214.171.124
Operating System:Windows XP Home Edition
Product Name:ZoneAlarm Pro