When you use any kind of web service for college related communications, including external services like Twitter, Facebook, YouTube, MailChimp, etc., you are required to follow campus communication standards and rules, including making your content accessibility compliant.
If you are not familiar with accessibility, there are some good resources, including an accessibility primer and a short online accessibility course, available on this website.
The issue I've noticed lately is the use of MailChimp to send out announcements that are nothing more than a scanned image of a printed flier. While it is okay to include a scanned image of an event's flier, you must also type out all of the information into the body of the email itself, so that anyone who might use a screen reader can obtain that information. This is because screen readers cannot extract text out of an image file.
This is especially important with MailChimp, as it does not give screen readers a proper indication that an image was included in an email. Thus, if an image is your only content in an email blast, it can look to screen reader users like you sent out a blank email.