Prevent 'via usermail.zohocreator.com' in email header

Prevent 'via usermail.zohocreator.com' in email header

Emails sent from Zoho Creator to GMail have this "via usermail.zohocreator.com".

I have tried setting up the SPF record to  v=spf1 mx include:zoho.com ~all  as suggested in https://help.zoho.com/portal/en/community/topic/which-spf-should-i-use and it doesn't work. This may be because the DKIM for usermail.zohocreator.com domain is present in the email header and Google identifies that to be more representative of the sender's domain. 

I have contacted tech support and have received frivolous replies that its for security (which I understand as preventing the mail from getting treated as spam) and cannot be modified. This is however unacceptable since this is a solvable issue.

Kindly consider allowing SMTP configuration in Zoho Creator or allowing setting of a DKIM header in the email sent through a creator app (Probably send the email content to a HTTP endpoint and get the signature)