A number of Zoho applications provide the option to send emails on your behalf (i.e. an email sent that comes from @yourdomain.com). In this article we cover the most popular applications in the Zoho Suite - if you send email from another application on your domain's behalf, or use other non-Zoho applications (i.e. mailchimp) you need to apply similar procedure.

Why is this important? Imagine, you receive an email from @yourbank.com.au, instructing you to change your password. It is very easy to "spoof" an email address like this - therefore email servers perform a verification upon receipt of an email - checking if that application is actually authorised to send emails on behalf of your domain. Failing this verification, and you email is marked as Spam, or even quarantined or outright rejected by the recipient's email server (this depends on how the administrator has configured the server).
DKIM and SPF are two items that must be set up on the DNS records for your domain. These DNS records are held at your domain registrar, or where your website is hosted. If you are not certain, contact your web-developer.

A DKIM record is made for each application - therefore if you have 4 applications sending mail on your behalf , you will have 4 records for DKIM - one for each application.

With SPF, you can only have one record for your domain. You include the other applications in that one entry. For example:
v=spf1 include:zoho.com include:transmail.net include:zcsend.net include:mail.zohoanalytics.com include:mailer.zohoshowtime.com ~all
Zoho Mail - in the control panel, go to Email Authentication and follow the instructions for DKIM and SPF. There will be a green dot (instead of grey) for DKIM, and a message for SPF when the setting is done correctly.
DKIM:
SPF:
Zoho CRM: Go to Settings - and select Email under Channels - click the tab Email Deliverability. Follow the instructions. If everything is set up correctly, you will see the green check marks.
Zoho Campaigns: Go to Settings and select Domain Authentication under deliverability. Follow the instructions for SPF and DKIM. When deliverability has been set up correctly, you will see the green check marks.
Zoho Sign: Go to settings and follow the instructions. When it is done correctly, you will see the status as verified.
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