In the constant fight against spam, a number of technologies are used to check and verify emails are sent legitimately. If your domain is not set up correctly, your emails may be treated as spam or even worse rejected.
MX Toolbox have an excellent free tool for checking the health of your domain for email. You'll find the free tool here:
https://mxtoolbox.com/emailhealth
Type your domain or email address into the box and click on the Check Email Health button.
After a few seconds all of the checks will have been completed, and you'll see a summary screen like below:
If any of the checks fail, you will see a list of Warnings and Errors.
Some common issues and how to fix them:
Reverse DNS does not match SMTP Banner
When a server receives an email, it checks which server it has come from. In a shared hosting environment, your domain name is on a server with lots of other domains. The name of the server will not match your domain name. This is only a warning and has no direct issues with email deliverability. You can ignore this.
Warning - Does not support TLS
Some mail servers (including Uptime's) will not offer a TLS connection unless it's asked for. The MX Toolbox check does not ask for a TLS connection. This is only a warning and can be ignored.
Not good! on Transaction Time
One common way to stop spammers is to delay the connection to the server on purpose. Spambots will try to connect and give up pretty quickly if they don't get an answer straight away. By delaying the initial connection, a legitimate email server will wait while spam bots will just move on to the next server. So even though this is shown as a warning it is on purpose and can be ignored.
DMARC Quarantine/Reject policy not enabled
Although shown as a warning this is a very important issue to fix. You will need to add a TXT record to your DNS defining your DMARC policy. We suggest using the following:
v=DMARC1;p=quarantine;sp=none;adkim=r;aspf=r;pct=100;fo=0;rf=afrf;ri=86400
