Hi Lourdes,
There are a couple of ways you could do what you're asking.
You could create five copies of the email you wish to send and use a smart campaigns to target the subsets of targets you'd like based on Random Sample, or other variable criteria (Member of Smart List is X, State is Y, etc.).
Alternatively, you could create a Segmentation with your different target groups segmented based on whatever criteria you wish. Then, in the email you're wanting to send, you change the header from Static Content to Dynamic Content, modifying the Reply-to field, Subject Line (and anything else you want) based solely on the segmentation.
We do something very, very similar with our sales emails, segmenting by sales rep territory. Whenever we create a personalized message—something meant to look like it's coming from a person's inbox—we change the Reply-To field and the Footer to match the rep and territory.
Hopefully that's helpful for your project! Good luck.