Direct marketing by email, text and similar electronic messages is covered by PECR, and the UK GDPR can also apply when personal information is involved.
Do not treat every address the same
The rules differ depending on who you are contacting and why. Marketing to individuals normally needs specific consent unless a valid soft opt-in applies. Some corporate B2B marketing is treated differently, but you still need to identify yourself and provide a valid way to opt out.
Respect the opt-out
People have the right to object to direct marketing. Keep suppression information so somebody who has unsubscribed is not accidentally added back into a campaign later.
Build permission into the journey
Good email marketing starts before the first campaign. Make the collection wording clear, keep evidence of how contacts were obtained and only use data for the purposes people would reasonably expect.
Official source: ICO guidance on direct marketing using electronic mail.
Need help planning an email journey? Explore Email Marketing.