Is it possible to add SPF and DKIM records to validate transactional emails from Zoho Invoice?
Yes. You can include zoho.com to your SPF (Sender Policy Framework)record. This entry represents all mail sending services of Zoho, and therefore including this entry would be sufficient if you use any other Zoho Product as well.
Note: Configuring this helps in cases where emails sent from customer addresses, might sometimes be caught in the recipient’s spam filter. To avoid this, we recommend you to add zoho.com in the SPF record of your domain’s DNS settings.
We hope that adding SPF record would be enough and there would no need for adding our public DKIM keys.
However, feel free to contact support[at]zohoinvoice[dot]com should you require any assistance on this regard.
Contact your domain provider to add zoho.com to your SPF record.