I have moved with personal and business email from Gmail to fastmail. My main problem with Gmail was that often emails from two unrelated customers where joine

I have moved with personal and business email from Gmail to fastmail. My main problem with Gmail was that often emails from two unrelated customers where joined in one conversation and I have mistakenly confused who I am communicating with. That happens if two unrelated people send an email with a title "problem with x" or "bug report". That hasn't happen in fastmail yet. One thing I am missing is Google search through email. Even though I have migrated emails from Google I still sometimes fallback to Gmail search over old emails.