In order to ensure the delivery of emails sent from your website (e.g. contact form, auto-replies, registration, etc), you will need to setup SPF and DKIM records on your domain DNS in order to make sure our mail servers can send mail on your behalf. (Read More <https://www.mailgun.com/blog/email-authentication-your-id-card-sending/>)
The SPF record specifies that alternative servers are allowed to send mail on your behalf. If you use Google Gsuite for your mail server (or some other third party mail service) you need to add their domain to the record. Plus you will add any other servers that send mail on your behalf, which means you need to authorize “mailgun.org” (our third-party mail service provider that sends mail on your behalf from the website). So the format of the value will look like the example below, and you will add an “include:[MYMAILSERVER]” for every extra server that sends mail on your behalf. (Read More <https://support.google.com/a/answer/33786?hl=en>)
Content: “v=spf1 include:mailgun.org include:_spf.google.com ~all”
*NOTE: only include the “_spf.google.com” address if you use Google mail.DKIM Record
DKIM is not required but it adds a higher level of protection for you by preventing others from spoofing mail from your domain, which in turn decreases the likelihood that your messages will be marked as spam. This works by telling the mail server to add a digital security signature to all mail sent. This is a manual setup process that requires that we create a public/private key on the mail server for your domain, and then you set up a matching DNS record for your domain with the public key. We can do this all for you for a one time $100 setup. (Read More from Google <https://support.google.com/a/answer/174124?hl=en&ref_topic=2752442&visit_id=637364477881238397-4173282704&rd=1>)
Content: “k=rsa; p=ABCDEFG1234567HIJKLMNOP890123ABCDEFG1234567HIJKLMNOP890123ABCDEFG1234567HIJKLMNOP890123ABCDEFG1234567HIJKLMNOP890123ABCDEFG1234567HIJKLMNOP890123/1a2B+ABCDEFG1234567HIJKLMNOP890123ABCDEFG1234567HIJKLMNOP890123”
*NOTE: this is a fake RSA key, you must generate a real RSA key on all your mail servers, e.g. Google Mail will give you a DKIM key, and we will give you one for our mail server specifically for your domain.