If everything is setup correctly, there could be trust issues.
It happens that mails sent from new IPs (IPs that never sent mails) have delivery issues. For some providers it will work absolutely normal, yet for some it will finish in spam or not delivered.
In case of Outlook.com
, they're know to absolutely block mails from new IP addresses.
For them, there is article on Outlook.com Postmaster.
Especially take at look at Are you sending email from new IPs?
:
IPs not previously used to send email typically don't have any reputation built up in our systems. As a result, emails from new IPs are more likely to experience deliverability issues. Once the IP has built a reputation for not sending spam, Outlook.com will typically allow for a better email delivery experience.
Take a look at note too:
Note: don't forget to update your Junk Email Reporting Program (JMRP) account with the new IPs. To update or set up a JMRP account, click here.
For GMail spam issue, you need to wait until trust you. If users whitelist your email address, that process can be speed up.
http://prntscr.com/cylm8j
mail-tester.com score
Gmail Original Meassage Result
Message ID xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx@mydomain.co.uk
Created at: Tue, Oct 25, 2016 at 8:53 AM (Delivered after 1 seconds)
From: admini@mydomain.co.uk
To: name@domain.com
Subject: new administrator for our site
SPF: PASS with IP xxx.xxx.xxx.xxx Learn more
DKIM: PASS with domain mydomain.co.uk Learn more
DMARC: PASS Learn more