Postman SMTP on "[Plugin: Jetpack by WordPress.com] Contact Form - email not sent to first address"

Hello JGB. What's the SENDER address (just the domain).

And is %26#x002c; valid notation? I don't think so. Try separating the addresses with a single comma only.

$to
(string or array) (required) The intended recipient(s). Multiple recipients may be specified using an array or a comma-separated string.
Default: None

(https://codex.wordpress.org/Function_Reference/wp_mail)