Ask HN: Are there any Fastmail clients that support sending with aliases?

I've been using Fastmail with wildcard aliases on a custom domain for over a year. In general, I love it, and I have few complaints. One area that I've run into trouble with though is accessing emails when I'm offline. This can be especially bad when I need to access tickets or other documents from my email in a place where I have no signal. Almost got stuck at the airport because I couldn't pull up a covid test that I'd saved to my email. Since the Fastmail app on iOS doesn't support offline emails, I'm looking into a third party client that does. There are so many clients out there, but one feature I'm having trouble finding is the ability to send emails from wildcard aliases. Are there any clients out there that support this?