I use Fastmail for personal e-mail for myself and two family members and where I work uses Microsoft's Office 365. I've never had issues with mails I send from

I use Fastmail for personal e-mail for myself and two family members and where I work uses Microsoft's Office 365. I've never had issues with mails I send from Fastmail landing in spam, even to Google users, and I prefer their webmail UI over Outlook for the web or whatever it's called these days.