Were they merely influenced by Egypt? Or did any Greeks go directly to learn in Egypt? I'm speaking about before the time of Alexander the Great.
According to commonly accepted lore, Thales was instructed by Egyptian priests [http://www.iep.utm.edu/thales/#H11], as was Pythagoros.
From Jay Lampert's article on teaching Egyptian philosophy to the APA:
Familiar commentaries on pre-Socratic philosophy typically refer to the issue of Egyptian influence only in passing, and many discussions of Plato's references to Egypt assume that Plato invented "Egyptian" sources for his own purposes. This may be largely true, but one cannot test this without a thorough background in both Egyptian and Greek philosophy. Unfortunately, very few scholars have expertise in both. Some classicists, linguists, and historians of religion read both languages, but few of these are trained in philosophy. As a result, many treatments of the possible influence of Egyptian philosophy on Greek philosophy are either thin on detail or polemical. On one extreme, one frequently finds the assumption that whatever the Egyptians were doing it was not philosophy. On the other extreme of the polemic, there is George C. M. James' Stolen Legacy: Greek Philosophy is Stolen Egyptian Philosophy (N.Y.: Philosophical Library, 1954).
If it's any consolation, Neoplatonism was created by an Egyptian, Plotinus, which had a big effect on a lot of Early Christian thought, but that's hundreds of years after Alexander.