I can send as the address, and emails arrive in my normal mailbox. I also use them for giving self-hosted services their own address/password to email me.
How's migadu's email ip reputation? Also do you have to create these identities in that admin panel to use or you can use it on the go like duck.com or Apple's hide my email?
Not sure on the reputation, but I personally haven't had any issues emailing people using gmail or microsoft. They have a good DNS Diagnostics page that checks all your domains DKIM/SPF/DMARC settings.
I've been using identities created in the admin panel, but they do have subdomain addresses where everything to *@user.domain goes to user@domain, and you can configure a 'Catchall' address (and of course 'plus addresses'). I haven't used either though.
