Deluge sendmail in Zoho Desk schedule can't send email from a verified email address

Deluge sendmail in Zoho Desk schedule can't send email from a verified email address

I am trying to add a scheduled action with ZDesk using a Deluge function that sends a weekly email to specific ticket client contacts

I've already verified the email address for use in ZDesk, but sendmail won't allow it in its "from:" clause. 
I've attached a screen capture of the error it gives:
"The function was not updated
The "from" address can only be zoho.adminuserid, zoho.loginuserid, or a verified email address. Please specify a valid email address and try again. LineNumber: 13"

I can use this email address to reply to ZDesk tickets without issue, but I just can't get sendmail to accept it as verified.
Please advise.

Thank you!