Is My Existing Express Consent Valid?

Yes! Your existing valid express consent is acceptable after CASL comes into effect. – See more at: http://bubbleboxmedia.com/casl-consent/#sthash.ObrNBkpw.dpuf

You must comply with CASL

CASL requires that a request for express consent contain all the prescribed identification and contact information. Express consent cannot be obtained via a commercial electronic message after CASL comes into force, unless you already have implied consent as defined in CASL. Remember: Under CASL, senders must retain proof of express consent, even if consent was obtained prior to CASL coming into effect.

source Canadian Radio-television and Telecommunications Commision; June 8 2014