Saving a draft email from within a contact

Saving a draft email from within a contact

Hi
 
If I compose a new email from within the emails section (of Zoho mail) there is an option to save as a draft
 
If I'm in a Contact, and open an email tracked to that Contact - then reply to or forward it - I can't see the option to save as a draft
 
Is there any way to do this?
 
This is important as I work on my emails late in the evening, then send the next morning - and I'd like to be able to do that for emails tracked to contacts
 
Thanks, as always
 
Ross