I'm a sole trader. A one man graphic design agency. Based in the UK. All my clients are in the UK or Europe.

Can I send my email newsletter to my clients? Even if they have not opted in?

I only have a select few clients. Perhaps 100 from my 15 years in business.

Nearly all of them know me well and I'm sure they wouldn't mind receiving an email newsletter from me.

Or would this contravene GDPR?

Someone has told me I can send the newsletter to clients who I have worked with in the last two years. But I'd like to be able to send it to all my clients.