[wtd]

iCloud (or its prior iterations) has had some bad press over the years ago about undisclosed filtering of inbound and outbound email and since then I haven’t considered them for email:

Outbound: https://www.cultofmac.com/103703/apple-may-be-invisibly-filt...

Inbound: https://www.macworld.com/article/2029570/silent-email-filter...