Former Trump adviser George Papadopoulos made a significant claim in an email: Top Trump campaign officials agreed to a pre-election meeting with representatives of Russian President Vladimir Putin.

The message, if true, would bolster claims that Trump’s campaign attempted to collude with Russian interests. But it’s unclear whether Papadopoulos, who pleaded guilty to lying to the Federal Bureau of Investigation, was merely boasting when he sent the July 14, 2016, email to a Kremlin-linked contact. There’s also no indication such a meeting ever occurred.