Hey, I created a droplet using the LAMP on Ubuntu 14.04 Application. And apt-get installed postfix and mailutil. Any time I send an email to Gmail it goes to the spam folder. My Zone file is as follows:

$TTL	1800
@		IN	SOA	NS1.DIGITALOCEAN.COM.	hostmaster.iio.io. (
			1402857717 ; last update: 2014-06-15 18:41:57 UTC
			3600 ; refresh
			900 ; retry
			1209600 ; expire
			1800 ; ttl
			)
             IN      NS      NS1.DIGITALOCEAN.COM.
                     NS      NS2.DIGITALOCEAN.COM.
                     NS      NS3.DIGITALOCEAN.COM.
			MX 10	iio.io.
*.api	CNAME	api.iio.io.
*.www	CNAME	www.iio.io.
@	IN A	188.226.244.148
www	IN A	188.226.244.148
api	IN A	188.226.244.148
@	TXT	"v=spf1 ip4:188.226.244.148 ~all"
mail	IN A	188.226.244.148
*.mail	CNAME	mail.iio.io.

And the received email is as follows:

Delivered-To: niall1402@gmail.com
Received: by 10.220.15.7 with SMTP id i7csp184731vca;
        Tue, 17 Jun 2014 02:28:48 -0700 (PDT)
X-Received: by 10.195.13.79 with SMTP id ew15mr35734652wjd.19.1402997327993;
        Tue, 17 Jun 2014 02:28:47 -0700 (PDT)
Return-Path: 
Received: from mail.iio.io (mail.iio.io. [188.226.244.148])
        by mx.google.com with ESMTP id b2si11777622wik.18.2014.06.17.02.28.47
        for ;
        Tue, 17 Jun 2014 02:28:47 -0700 (PDT)
Received-SPF: pass (google.com: domain of niall@iio.io designates 188.226.244.148 as permitted sender) client-ip=188.226.244.148;
Authentication-Results: mx.google.com;
       spf=pass (google.com: domain of niall@iio.io designates 188.226.244.148 as permitted sender) smtp.mail=niall@iio.io
Received: by mail.iio.io (Postfix, from userid 1000)
	id EB8C9201AF; Tue, 17 Jun 2014 05:28:46 -0400 (EDT)
Subject: morn test 2
To: 
X-Mailer: mail (GNU Mailutils 2.99.98)
Message-Id: <20140617092846.EB8C9201AF@mail.iio.io>
Date: Tue, 17 Jun 2014 05:28:46 -0400 (EDT)
From: niall@iio.io

test morn 2

I've tried editing the SPF1 record and MX record. I've renamed the droplet to mail.iio.io. I'm not sure why it's still failing and what I can try next?