I need to separate natural, coherent text/sentences in emails from lists, signatures, greetings and so on  before further processing.
example:

Hi tom,
last monday we did bla bla, lore Lorem ipsum dolor sit amet, consectetur adipisici elit, sed eiusmod tempor incidunt ut labore et
  dolore magna aliqua.

list item 2
list item 3
list item 3

Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquid x ea commodi consequat. Quis aute iure reprehenderit
  in voluptate velit
regards, K.
---line-of-funny-characters-#######
example inc. 
33 evil street, london
mobile: 00 234534/234345

Ideally the algorithm would match only the bold parts. 
Is there any recommended approach - or are there even existing algorithms for that problem? Should I try approximate regular expressions or more statistical stuff based on number of punctation marks, length and so on?
You'll need many heuristics to get an approximation of a solution, so here's one: you can safely cut off anything after a sigdash (hyphen-hyphen-space), which standards-conforming e-mail messages use to separate the message body from the signature.
Another approach you can use is to store copies of e-mails from the same sender; this should allow you to extract things that are the same or similar in every message (such as salutations and signatures) and detect how their mail client does quoting.
Algorithm to match natural text in mail