Emailing End User, Not Purchasing Dept

Suppose you sell a B2B software, and you want to send emails to help the end user understand how to get the most of out it - how to ensure the right person is getting the emails?

Many companies will be using a purchasing dept or at least someone higher up will be paying. Does that mean they, instead of the end user, will be getting detailed instructions that they're not interested in?

I presume this issue is tackled in an existing neat and elegant manner? If so, could someone tell me what it is, as this is bugging me... :)