So far IBE has been mildly usable. Most people were able to get it and login and read the message without any problem.
As supsected a few people were skeptical of the email and didn't want to open it until I called them since it doesn't look like your typical email.
I also had a few people have problems with it including:
#1 my boss couldn't open it on his cell phone - didn't work at all. Also he didn't want to "sign up for an account" even though I explained that's not what it is.
#2 Someone on AOL couldn't open it at all.
#3 One of my customers using Electric Mail and also I think another provider could not open the message. She tried a few different times today...going to have to call tomorrow and see if we can figure this out.
#4 Couldn't respond to tickets to my data center which is a pretty big hosting company. They have an automated system and the message came as an attachment which was then not included in their automated messaging system.
#5 I was told after asking if I could use it on a web server to send messages that it only works in Outlook - after I told them I was using Outlook already so obviously I know that. So you can't sign up for this and then send secure messages in an automated fashion to potential clients, for instance, or email receipts from an e-commerce web site or links to file downloads, etc.
A few things to resolve here...it's not quite as simple as normal email and obviously doesn't work for all scenarios.