Anyone managing email campaigns inside their CRM?

Been rethinking how we manage email campaigns alongside our CRM as things start to scale. We’ve tried a couple of different approaches, but I’m still not fully convinced what works best long term.

At lower volumes things seem fine, but as sending increases, deliverability and overall workflow start getting tricky. Curious how others here are handling this. Are you keeping everything close to the CRM or relying on separate tools?