1) One technique that might work is to replace all the occurences of '>,'  with something else (like '###', then remove the remaining commas, then replace al the '###' with '>,' again.

Regular expressions with nested content / matching pairs can be delicate to create. This is true whatever the language...
Java might not be the best language to process text, but it is very able at this task, so I don't see why students of Processing or Java should go learn another language for such goal. It is good to know more languages, but time is often lacking, and when I see people struggling already with a language, it might not be the best time to learn another...
Beside the fact that if they are students, their teachers might not be pleased to see a non-Processing result...
The same can be true in an enterprise: you shouldn't need to spawn another program in another language just to do a parsing task. But fortunately, for complex tasks, you have good libraries, like Parboiled.

Back to the question. The trick given by jbum is good, if your input data is regular enough, ie. always have the separating comma immediately after the closing angle bracket. It is the simpler and faster way, so use it if it works for you.

Otherwise, you need a more sophisticated regular expression to isolate these inside commas: replace them with some special char, split, replace back the special char with comma.

1. String test = "\"Talboom, Esther\" <E.Talboom@wegener.nl>,     DRP - Wouter Haan <wouter@drp.eu>, \"Wolde, Jos van der\" <J.vdWolde@wegener.nl>,   \"Debbie Derksen\"  <deberken@casema.nl>,   corine  <corine5@xs4all.nl>, clankilllller@gmail.com, \"Markies Aart\" <A.Markies@wegenernieuwsmedia.nl>";
2. // Match either simple "foo" strings (to avoid matching double quotes in isolation) or "foo,bar" strings
   
3. Pattern p = Pattern.compile("(\"[^,\"]*\")|(\"([^,\"]*),(.*?)\")");
4. Matcher m = p.matcher(test);
5. while (m.find()) {
6.   println(m.group(0));
7.   if (m.group(2) != null)
8.     println(">> '" + m.group(3) + "' '" + m.group(4) + "'");
9. }

I agree with phi.lho. It wasn't my intention that you drop Processing like a hot potato, merely that you convince your teacher to give you better assignments.  :)

both thanks, it's not always like >, if it's only email and no name then the < and > are missing. But it was a good idea. I will give phi.lho's pattern a try.

What is a good way to replace, now i get this back:

thanks!