Controls whether or not to send membership level expiration emails. Passes the boolean true or false and the user ID.

apply_filters( 'pmpro_send_expiration_email', bool $send_email, int $user_id );

Parameters

$send_email

bool; Whether or not to send the email (default: true)

$user_id

int; The user ID being sent this email

Source

File: https://github.com/strangerstudios/paid-memberships-pro/blob/master/scheduled/crons.php