CASL applies to 'commercial electronic messages'. This means that most (but not all) communications sent from charities are completely exempt from the requirements as they wouldn't be considered 'commercial'.
Soliciting donations is okey dokey, as long as the charitable donation # is included.
Things to be careful about (may void the exemption):
- paid advertisements (funders/sponsors might be a grey area)
- promoting programs/courses "offering services to individuals who may benefit, where there is a cost-recovery element (for materials, for example)"
- internal job advertisements (because there's a commercial aspect, this may also be a grey area)
Even if a message is not exempt, it can still be sent as long as all of the usual CASL requirements are met.
More charities should be taking advantage of this! There are LOTS of things a charity could include in its newsletter strategy... and much more leeway with list building if CASL doesn't apply.