If you know Unix commands and can afford to rent your own servers, all of you should run their own:

• email server ( https://mailinabox.email/ )
• matrix server ( https://github.com/spantaleev/matrix-docker-ansible-deploy )
• fediverse server ( https://soapbox.pub/ )

You will need about 30 USD per month, to own all of this. For Email and fediverse you only need to rent a 5$ per month server. But for matrix you will need a 20$ per month server.

For Emails, .com emails do not go to SPAM easily if you configure it right, so you should IMO get a .com domain. For emails using mailinabox.email, you can create unlimited aliases. e.g. if your email is [email protected], you can also create [email protected], and use it to sign up just for paypal. So all email from paypal and anyone paypal sells your email to will be sent to [email protected], which you can then used filter emails.

For fediverse server and matrix server, disable registration.

Finally, do not use Google Cloud, AWS, Oracle, Digital Ocean, or Linode. I use vultr for hosting. Alibaba Cloud is also a good option.