🇨🇦 Canada
Under the regulation of Canada's Anti-Spam Legislation (CASL) you may message (SMS or email) a lead obtained by referral once before obtaining consent.
The policy states:
"There is an exception to the consent requirement for the first commercial electronic message (CEM) sent following a referral or recommendation if certain conditions are met:
The referral must be made by an individual who has an existing business relationship, an existing non-business relationship, a family relationship or a personal relationship with the sender and any of those relationships with the recipient of the CEM.
Also, the full name of the individual who made the referral and a statement that the CEM is sent as a result of a referral must be in the CEM. Only one CEM may be sent without obtaining the consent of the recipient of the message.
The CEM must still respect the other two requirements – it must contain the identification information and an unsubscribe mechanism."
See here for more detail: https://crtc.gc.ca/eng/com500/faq500.htm
🇺🇸 US
Under the regulation of CAN-SPAM, any commercial email must provide an option for the recipient to unsubscribe from further communication.
The policy states:
"Tell recipients how to opt out of receiving future email from you. Your message must include a clear and conspicuous explanation of how the recipient can opt out of getting email from you in the future. Craft the notice in a way that’s easy for an ordinary person to recognize, read, and understand. Creative use of type size, color, and location can improve clarity. Give a return email address or another easy Internet-based way to allow people to communicate their choice to you. You may create a menu to allow a recipient to opt out of certain types of messages, but you must include the option to stop all commercial messages from you. Make sure your spam filter doesn’t block these opt-out requests."
See here for more detail: https://www.ftc.gov/tips-advice/business-center/guidance/can-spam-act-compliance-guide-business
🇦🇺 Australia
You can message a referred lead so long as 1) the purpose of the communication is clear, and 2) there is an opt out mechanism.
See here for more detail: https://www.oaic.gov.au/privacy/australian-privacy-principles-guidelines/chapter-7-app-7-direct-marketing
🇳🇿 New Zealand
When messaging a referred lead:
You need to clearly and accurately say who you are as the sender.
There must be a clear and easy way for the person receiving your commercial electronic messages to unsubscribe or stop receiving them.
See here for more detail: https://www.dia.govt.nz/Spam---Commercial-electronic-messaging-in-New-Zealand