Automation e-mails not sent when using only the BCC field

Issue Summary

Automation e-mails are not being sent when all addresses are placed in the BCC field

Steps to Reproduce

1. Add a Send Email action to an automation rule
2. Add addressees only to the BCC: field, leave the TO: field blank
3. Execute the automation

Expected Results

All addresses in the BCC field receive the e-mail sent by Automation

Actual Results

No e-mail is received

This is what appears in the Audit log:

Workaround

Add at least one e-mail to the TO: field, then the BCC e-mails will receive the message as well