Linode is one of the most popular cloud hosting solutions at the moment and with good reason. With over two decades in the industry Linode is the largest independent open cloud provider in the world with 11 global data centers serving nearly a million customers and businesses around the globe.

Linode is the cloud provider of choice for us here at Loopdesign, and after starting to move some of our sites over to them I noticed a small issue that might catch out some people new to their systems. As of Tuesday, 5 November, 2019, in an effort to reduce the amount of spam being sent by users on their platform, Linode have blocked SMTP ports 25, 465 and 587 on all new Linodes by default. This means that if you spin up a new Linode instance using something like their WordPress One-Click App, you won't be able to send email using that server.

To get the SMTP ports opened you need to do a few things.

1. Make sure you have a domain A record pointing to your server.
2. Setup reverse DNS on your linode in the control panel. To do this enter your linode in the Linode control panel. Enter the networking tab and at the bottom of the screen select the entry for the valid IPv4 address of your server and overwrite the RDNS entry with your valid domain.
3. After the above steps are done you can open a ticket with Linode support and request that they open the ports for you.

This might sound time consuming but Linode support are excellent. The first time we went through this process it took a matter of minutes to implement the settings and just a few hours for Linode support to action my ticket.