I have a mail problem that I suspect is really a DNS problem.
My hosting company has apparently given me the subdomain li173-195.members.linode.com. I have another domain, woollymammothlabs.com, that points to the same IP as li173-195.members.linode.com.
When I send mail to email@example.com, I get it. When I said mail to firstname.lastname@example.org, I get an undeliverable message.
What am I missing?
(I'm on Ubuntu and I'm using Postfix.)