Can Hazel Read Saved Emails.

Question:
My initial experiments suggest that Hazel cannot emails saved as .eml to a folder, is that correct.
Background:
I'm working on a process to save emails from mail.app to DevonthinkPro.
I'm using Hazel as the final step to move the email from the folder into DevonthinkPro
I can accomplish this if I save the email as .rtf or .pdf but I'm experimenting with just saving the email in raw form.
With my draft Hazel process when I run the "Preview" it appears that Hazel cannot read anything inside the email, not the address, nor any of the content.
Is my assumption that Hazel cannot read the email correct?
A related question is "What does the parameter "Source URL/Address" refer to? In the manual the explanation is as follows
However, if Hazel can't read an email its not clear to me how this would be used.
Thanks
My initial experiments suggest that Hazel cannot emails saved as .eml to a folder, is that correct.
Background:
I'm working on a process to save emails from mail.app to DevonthinkPro.
I'm using Hazel as the final step to move the email from the folder into DevonthinkPro
I can accomplish this if I save the email as .rtf or .pdf but I'm experimenting with just saving the email in raw form.
With my draft Hazel process when I run the "Preview" it appears that Hazel cannot read anything inside the email, not the address, nor any of the content.
Is my assumption that Hazel cannot read the email correct?
A related question is "What does the parameter "Source URL/Address" refer to? In the manual the explanation is as follows
This is the URL or email address the file came from. Note that only certain programs store this information, such as Safari and Apple Mai
However, if Hazel can't read an email its not clear to me how this would be used.
Thanks