You can set up a custom domain to allow Greenvelope to send email on behalf of your email server. The advantage of this approach is that it will allow your invitations to be sent from an email address that your guests already recognize and may already have in their address book. It also will remove the “via” header in many email clients, like Gmail.

For example, invitations will come from you@yourdomain.com instead of greenvelope@invites.greenvelope.com.

To take advantage of this feature it is necessary to set up a DKIM public key in your domain’s DNS records. This allows receiving email servers to verify mail coming from Greenvelope on your behalf is allowed. To ensure maximum deliverability, Greenvelope encourages you to be sure your domain publishes a DMARC record.

The DNS TXT record needs to be created under:

gvdkim._domainkey

The value for the key needs to be:
v=DKIM1; k=rsa; p=MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEA0ZBPuu+aQXqQk05iuZ9CPLY5mWrNUjE0KPpzN5YWpOHxmk2q0Yy+p/9NwAFPDiZzJ+Khfnx911lYw1H83yQSa5pa4IdrpasNHh+7KTE7DCmpu+wrp+TZocM2vHmMjNehMxAGpl6JqDtjUkVE0qAYrWCfKpcwjkY+4fY23qQXpgO3YUHqWqSBLCx/Htv63LiFuqdpHH6hbNeZi0qNoWjRHFAZ0iibEPOJ9Zi9tDPkqbpqQmJciteBHnj0magZ3WC3mloeGA+Oegds9Yu03VoeJikemr0opknA+pQi0rxpelb0/5cuJ/Bf+zDVkUWQwzlgwETg4PX83X8rNCFWh8IyiQIDAQAB

Note: When you copy and paste the key line breaks may be introduced, which will cause the key to be invalid. Be sure to remove any line breaks when setting up the value. 

Some DNS providers do not support TXT records longer than 255 characters. You will need to break the key into two parts to save in one TXT record. More Information here