After testing your domain name, nothing was found to indicate there is a problem with your domain name, rDNS, SPF, or any other part of your DNS or configuration.
Here's a link to a report which shows you as clean: http://www.dnsinspect.com/palace-designs.com/1412187069
Here's a more specific MX server test which also indicates no issues seen.
Clicking on the red 0, under the RBLs header, will open another window which will show you your RBL (real-time blacklist) status, and indicates you are on none. Note that sometimes this list shows MX servers on Brazilian lists, but, unless you regularly do business in Brazil, they can be ignored.
You can replicate this at: http://www.dnsstuff.com/mstc. A free account is required:
With the exception of three minor issues, show below, your server also tests clean in another reporting tool.
This test can be re-created here: http://www.dnsstuff.com/tools#dnsReport|type=domain&&value=palace-designs.com, but will require a free account ot do so:
When testing directly to the e-mail address you supplied, both to me personally, and in the original post, the message is rejected as MAILBOX DOES NOT EXIST:
Could not deliver message to the following recipient(s):
Reason: Remote host said: 550 Requested action not taken: mailbox unavailable
-- The header and top 20 lines of the message follows --
Received: from REDACTED (REVERSE_IP_ADDRESS_REDACTED-Illinois.hfc.comcastbusiness.net [CLIENT/DEVICE IP ADDRESS REDACTED]) by securemail.chicagonettech.com with SMTP
Wed, 1 Oct 2014 13:29:57 -0500
Date: Wed, 1 Oct 2014 13:30:01 -0500
Organization: ChicagoNetTech Inc
X-Mailer: Microsoft Outlook 14.0
This is a multipart message in MIME format.