So I just set up postfix for the first time (on OS X) and am getting this error"
Jan 25 15:45:09 localhost postfix/smtp: 204D448A29A: to=<firstname.lastname@example.org>, relay=none, delay=30, delays=0.01/0.01/30/0, dsn=4.4.3, status=deferred (Host or domain name not found. Name service error for name=domain.com type=MX: Host not found, try again)
I can tell it's a DNS issue, but haven't really found a fix for it: :(
Reading, but don't quite understand:
So I changed my error to this:
Jan 25 16:23:37 localhost postfix/master: fatal: open lock file pid/master.pid: unable to set exclusive lock: Resource temporarily unavailable