Is there a way to have CiviCRM create contacts from email addresses found in the body of an inbound email? We have a number of different sources that send us emails with addresses in the email bodies that we want to capture (for example, we receive volunteer applications from a form on our website, and also from VolunteerMatch - both contain the applicant's email address in the email body). However, it looks like inbound email processing only parses email headers by default. Is there something obvious we're missing?
This would require an extension to do.
That said, I'm not sure this is the best approach for your use case.
If you have a form on your website, it seems like it would be better to integrate that form directly with CiviCRM instead of using inbound email processing. For VolunteerMatch, I would use their API with Form Processor to process the message rather than inbound email processing.
That second item is a complex solution if you're new to CiviCRM, but within the reach of a non-coder, as opposed to writing an extension.