I need to send my online banking clients an email to upgrade to a supported browser for the best online banking experience. I am NOT soliciting for new products or services. I am investigating using an email marketing tool (i.e. Constant Contact, MailChimp, etc) so that I can get data on bounces, spam, etc. All the solutions I am looking at require that the customer be given the option to "opt-out" of further email communications. For this type of email communication am I required to provide opt-out? I have limited ability from within the online banking solution to send targeted secure email and we don't provide opt-out for "hey...the system is going to be down for the next hour" or "remember we'll be closed on Christmas Day" emails.

It sounds like your messages fall squarely into the "transaction or relationship message" (TORM) category described in the CAN-SPAM Act, Section 3, Definition #17. Take a look at the FTC's "Compliance Guide for Business". The "Guide" tells you that a TORM "may not contain false or misleading routing information, but is otherwise exempt from most provisions of the CAN-SPAM Act." If you are considering solutions that cannot support a "TORM-only" message flow, keep looking.

Constant Contact and Mail Chimp are geared to marketing messages.