SugarCRM: Create DRAFT Email via SOAP

Question

Hello, Is it possible to create DRAFT emails via SOAP?

I've got this custom button which generates an invoice number upon clicking (via AJAX) and updates the Lead screen with the number. Behind the scenes a PDF file bearing the same invoice number is generated and attached to the Lead as a NOTE (with the PDF as note attachment).

However, this calls for an extra step, where a user has to DOWNLOAD the attachment first and then re-upload it as an email attachment before the user can send it out to the Lead.

So... is there a way by which I can create a DRAFT email with the PDF as an attachment. The user then just needs to visit the emails screen, type in a word or two and hit SEND.

Thanks, m^e