Kopi allows you to "bring you own domain". That means instead of using forwarders defined on the shared domains like "kopi.cloud" or "kopimail.net" - you can use your own registered domain. No need to worry about selecting an unused keyword when you own them all!
Plus of course, you're then not locked in to Kopi - you can take your domain and define a different mail exchanger service whenever you want.
You must have your own domain registered with a DNS provider. Your DNS provider must allow TXT and MX records to be added to your domain.
The examples below use cloudns.net as the DNS provider.
Registering your domain with Kopi
You must register your domain with Kopi so that it knows about your domain and so that you will be able to create a forwarder for that domain.
Add a verification DNS record to your domain
When the domain is first added to Kopi, it will have a status of "Pending" - that means you the domain has not yet been verified.
In order to prove that you control the domain and that you authorize Kopi to handle mail exchange for the domain, you must add a TXT record containing an authorization token.
Click the "DNS settings" button in Kopi and you will be shown a verification token:
Create a new DNS TXT record with the host set to "_amazonses.kopidomain.dns-cloud.net" and the value set to the verification token provided by Kopi.
Notice the "_amazonses" prefix sub-domain for the record:
Once you've correctly added the record to your DNS record set, you may need to wait a few minutes for the DNS to propagate and for Kopi to recognise that the domain is verified.
You can click the "Update" button to force Kopi to check the status, but note that even once the DNS record has been made available, Kopi managed domains work via a polling mechanism and it still may take some time for the verification to proceed.
Note that the TXT record must remain available via DNS for the domain remain available. If the authorization record is removed, the domain status will be changed back to "Pending", then after a certain amount of re-tries, the status will change to "Failed".
Add a DNS "MX record" to the domain
The next step is to declare that you want to use Kopi as your mail exchanger by publishing an MX record.
Kopi uses AWS SES for forwarding mail of managed domains. You must declare that all mail should be delivered to SES by setting your MX record to point to "inbound-smtp.us-east-1.amazonaws.com":
The '*' character is a "wildcard" domain specifier that declares all subdomains use Kopi for mail forwarding.
Using a single sub-domain for each Kopi forwarder
If you don't want to use a wildcard domain MX record, you must create an MX record matching the name of each Kopi forwarder. For example, if you were to create a forwarder for "@mail.kopidomain.ndns-cloud.net" you would need to matching MX record with "mail.kopidomain.ndns-cloud.net" as the host value.
Remember to create your Kopi forwarder
After your domain is correctly configured and verified, you still need to create a forwarder.
Note that your domain is now an option in the "domain" dropdown. Given the example above, an email sent to "firstname.lastname@example.org" will be forwarded by Kopi to your real address.