While we dont' use MailChimp as our email provider I find this posting in the MailChimp Knowledge base and found it very helpful. Note this is a cut and pasted from the MailChimp site - here's the original link. Also there's a link at the bottom to Is My List Okay To Use In MailChimp? which is somewhat the same but has more information for different scenarios to help you understand and mitigate possible issues.
From the MailChimp site:
|Your list is okay
||Your list is NOT okay
- People who have opted in to your list on your website
- People who have opted in to receive emails from you offline
- Your customers who have a prior business relationship with you (but if you haven't contacted them in ages, be sure to send a re-introduction email)
- People who opted in to receive emails from you at a co-registration site
- You're sending on behalf of your customer, and they comply with the above.
- People who purchased one of your products, or attended an event, and gave you their email address so they could receive updates from you.
- Your internal employee list (such as for company notices)
- Press releases sent to reporters who signed up at your website
- Lists that you purchased from a 3rd party (even if it's "opt-in")
- Even if Chuck Norris or GOD HIMSELF sold you the list, it's not okay to use in MailChimp.
- Lists that you are renting from someone else
- Lexis-Nexis, Real Estate MLS databases, Advertising Redbooks, AdBase lists, D&B, Experian
- Lists from a local Chamber of Commerce or local club or organization.
- Do NOT export your entire email address book into MailChimp [Here's why]
- Emails that you "scraped" (either manually or automatically) from other websites
- You may not send personal resumes to potential employers. They did not opt in to receive emails from you.
- Recipients whose emails you collected without their permission, but you think they could really use your product or service, and you think they'd really want to hear from you.
- Members of a group/organization who never asked for your emails (even if you're a member of the group)
- Unsolicited press releases to reporters
- Lists of customers who dropped their business cards in a fishbowl, but they had no idea they were going to receive emails (because you didn't say that on the fishbowl).
- Lists of registered voters in your district obtained from your local government.
Still not sure? Even more details on lists that are and aren't ok and possible list scenarios!