Currently there is no way to trigger workflows from a manual email being sent. Having this functionality will allow replies and opens of manual emails to trigger Workflows and allow contacts to get quick automated responses. Currently it requires a manual email to be sent and then manually moving the contacts to other Opportunities or tagging them manually.This is fine for a few contacts, I have 14,000! Having a 'subject' option within Workflows would allow an email subject line to become the trigger. The current "contains phrase" option does not allow for this to work as it needs a trigger phrase to be in the body of the email.

HIGHLVL-I-4064