Error when adding BCC to email handler with webforms and smtp I use SMTP to handle emailing and Webform to generate my forms on a drupal just upgraded to 8.7.10

I have recently discovered an issue where webforms that have an emal handler set to include a BCC email address throw the follwing error:

error: Call to undefined method Drupal\smtp\Plugin\Mail\SMTPMailSystem::_get_components()


The form submission does get saved but the confirmation process breaks so the user is not notified the submission saved and no emails of any kind are sent out. 

Not including BCC fixes the problem. I use BCC in email handles to debug on a number of my sites and have never had this issue before. Any ideas? Is this a problem with webforms or smtp modules?
It looks like the issue lies with the SMTP module. The release notes for 8.x-1.0-beta6 include a bug fix for:

#2993124 by jmuzz, qichanghai, Chris Matthews: Call to Undefined Method error _get_components when there is a BCC