If I use the zoho web client to send mail it includes a valid DKIM, but if I send by an external client via zoho smtp no DKIM is included in the email header. I have correctly configured the SPF
Authentication-Results: mx.zohomail.com;
spf=pass (zohomail.com: domain of nursecentral.com.au designates 45.124.52.213 as permitted sender) smtp.mailfrom=
admin@nursecentral.com.au