DNS setup for Digital Ocean
Log in to the control panel of Digital Ocean. Click Networking in the main menu, then click on the domain you would like to manage.
Select the record type of CNAME.
Enter the Hostname we recommend into the HOSTNAME field.
You only need to add the first part of the recommended hostname without the domain name appended to the end as it will automatically be added.
Enter the Value we recommend into the IS AN ALIAS OF field.
The TTL can be left as 3600.
Click 'Create Record' to save the record.
Note: The hostname and value can be found in your SMTP2GO account on the 'Settings > Verified Senders' section.
Repeat the above process to add all three CNAME records. Once added, they will show as verified on your SMTP2GO account's Sender Domains page once the updates have propagated.
Further detail in regard to adding DNS records to Digital Ocean can be seen in their DNS management documentation.