Unless you intend to interpolate, you should never use double-quotes. In
this instance, it was actually impactful -- `$myhostname` and
`$mydomain` were meant to be left as-is, referring to those Postfix
config parameters, but were accidentally interpolated and subsequently
generating nonsense (but not fatal) configuration.

This fixes the output "WARNING: apt does not have a stable CLI interface. Use with caution in scripts."

New line in the final output, looks way better!

Some strings will escape and break the script, inserted fixes like single quotes ( ' ' ).

Make gmail's less angry