Reefer Mail was formed out of necessity:

We found that major email providers like MailChimp and ConstantContact do not allow for the cannabis industry to use their services. Yes, you might be able to get by for a bit using their system, however if your receive a few complaints then they are likely to shut off the account. How do we know this? We have had over 50 accounts closed! As a division of Green Scene Marketing, we have used every system before we decided to make the move to our own hosted platform.