said by SparkChaser:
If you take a look at my post above, what should I be using to stop that type of intrusion?
Well, my first answer would be to not respond to [any] e-mails purportedly from Linked-In. However I realise that you might say it's necessary for your business.
My second point would be to ask if you are using a Microsoft e-mail program. If so, I would consider an alternative such as Thunderbird. This is especially true if you are using an older MS e-mail program.
In any event, your e-mail program should be set to screen for spam/phishing/malware, to block scripts and active content, and (unless you need them) to block images.