A period could very well have worked there, but as Ben Crair
observes in the New Republic, they often seem too severe; and
exclamation points, the kudzu of punctuation in the digital age,
might make you feel like an overenthusiastic phony. But the
semicolon’s breezy informality, for me, captures the unstructured,
colloquial nature of digital correspondence more so than any other
punctuation mark out there.