At cold.email this is our current stack that we get good results with. Findymail.com, and Wiza for email finding and validation with 95% deliverability. Porkbun for domains for Sending Infrastructure Inboxkit for MS and Gmail inboxes Clay + 4.1 nano for Copywriting Instantly.ai for Warmup and Sending ONLY Python + Serper.dev + AI Web Researcher in Clay for list building and validation Icypeas dataset for list building. Custom APIs in house