Setup DKIM

DKIM consists of two parts: 

1. A DNS record with a public cryptography key that is used to verify whether a sender is authorized to send an email for a specific domain
2. A private key that is used to sign an outgoing email. 

Adding a DKIM record to a domain’s DNS follows almost the same steps as adding an SPF record.

Step 1: Create a domain key for your website

Use any tool available based on the operating system to create a domain key for your website.

Step 2: Add a public key to the DNS entries for your domain

This key can be used by email servers to validate DKIM signatures in your emails. Here’s a list of the most popular DNS providers with links to official and third-party documentation. You can refer to these to help you with TXT and DNS record setup.

1. Amazon Route 53: SPF and DKIM
2. Bluehost: Setting up DNS
3. Cloudflare: General DNS help
4. Dreamhost: SPF, DKIM
5. DynDNS: Setting up DNS
6. GoDaddy: SPF and DKIM
7. HostGator: Setting up DNS
8. Hover: Setting up DNS
9. Namecheap: SPF, DKIM
10. Network Solutions: Setting up DNS
11. Rackspace: Setting up DNS
12. Rackspace Cloud DNS: Setting up DNS
13. Register.com: Setting up DNS
14. United Domains: DKIM and SPF (in German)
15. ZoneEdit: Setting up DNS
16. Marketo: Setting up DNS
17. Infusionsoft: Setting up DKIM
18. Shopify: DKIM and SPF 
19. Sparkspost: Setting up DKIM
20. Yandex: Setting up DKIM
21. Mandril: Setting up DKIM

Step 3: Begin applying a DKIM signature to all outgoing messages by enabling DKIM signing

Setting up a DKIM signer on a mail server is another integral part of the process, which is a difficult task for many email systems. The only exception is Google’s G Suite, which provides a clear how-to tutorial for setting up a DKIM signer. For Microsoft Office 365, users can take advantage of Microsoft’s comprehensive guide on how to implement DKIM signing on that platform.