SendRecurring - SendRecurring allows you to setup, send, and maintain scheduled email reminders.

Attio - Attio is a radically new type of CRM that is real-time, entirely customizable and intuitively collaborative. Using Attio, your team can create, build and deploy your CRM exactly as you want it.

Recurrr - Send recurring emails

Overloop CRM - Everything starts with a good conversation.

Followup.cc - FollowUp for email is a lightweight productivity suite that keeps your conversations and tasks from slipping through the cracks. Set perfectly timed reminders that arrive at the top of your inbox, right when you need them.

HubSpot - Grow Better With HubSpot: Software that's powerful, not overpowering. Seamlessly connect your data, teams, and customers on one CRM platform that grows with your business.