[Users] Limitations of Python scripts

[alb348 at gmail.com]

Hi

I am trying to understand the limitations of Python scripts in Claws Mail.
According to a Youtube tutorial, only menu commands are accessible.

Does this mean that accessing the actual contents of an email and 
processing it cannot be done?
What I have in mind is:
accessing the email content, searching for keywords, maybe replacing 
some of the text, saving the message, making a clone of the message and 
saving it somewhere else, triggering some external programs (not Python 
scripts) in the event a given string is found in the message, etc...

Can these functions be done via Python scripts?

More in general, I would like to know from someone who uses the Python 
scripts in CM intensively how they work overall, and what are their main 
limitations.

Thanks

Alby