Best Affordable Email Automation Tools for Founders

Hey all, If this is already covered in detail in another thread, please let me know and/or point me there. Looking for feedback from the community (know Clay doesn’t recommend integrations directly) I am getting into inbound/outbound automation via clay and want to know what the best/more affordable emailer is. I’m keen to weigh cost vs ease of use. I am a founder spread thin and would prefer to tool that will require the least about of troubleshooting. I know Smartlead.ai and Instantly are commonly mentioned, Is there a preference between the two & any other recommendations and why? Thanks in advance for any guidance here.