Hi Fatima -- I would suggest Substack AND Medium. Focus on growing your Substack list and repurpose your content on Medium. You have more control with Substack than with Medium. And if you want even more control, you can go with ConvertKit :) That's my email newsletter platform of choice -- they're offering a free 30 Day trial on their pro plan, here's my affiliate link if you're interested: https://convertkit.com/email-marketing-fresh-start?lmref=lQ4XIA