US Email Providers - Other then Google, MS, Apple, ...

I need to change ISPs and need to find a new email provider. This time I want to move to my own domain which I purchased through Namecheap and I do not want to use another ISP's email system nor do I want to use Google, or Microsoft since I am Linux (and Android too) based. I would like this to be US based or at least have a strong US presence so obvious choices like Proton Mail, Mailfence, and Mailbox.org are out. I would prefer it interoperate well with FOSS software too, I use Thunderbird and K-9 Mail for example. Also so want them to be trustworthy, have good security, and have good OpSec with respect to their their servers and service.

After looking I find three I am considering and they are quite different:

• Fastmail. Long history. No PGP support but they do have their own domains one can use also.
• Namecheap Private Email. Uses Ox App Suite, may support PGP, and quite new. I think you have to have your own domain (not sure).
• Forward Email (forwardemail.net). A forwarder with IMAP support. You supply the webmail if you want webmail, but otherwise it should work fine with IMAP and normal clients.

So questions:

• Any thoughts and experience, pros and cons with the above 3.
• Other better ideas.

So thoughts? Thanks.