On: Solving My Email Problem

[funkaster]

how would that work ? don't you need to set up the MX records for that particular subdomain?

[danieldk → funkaster]

You set up wildcard MX records, such as for *.yourdomain.tld.

With Fastmail sets this up automatically if you let them handle your DNS, though you can (obviously) disable it.

[fredsted → funkaster]

you could set up a wildcard CNAME

[jlgaddis → fredsted]

Please don't. Per RFC, an MX RR cannot point to a CNAME.

[fredsted → jlgaddis]

That's not what I'm suggesting though.