No invoice has gone out by e-mail since Friday

Fiducia Atlas (a fictitious accounting firm) sends its invoices, reminders and tax filings by e-mail from its management software, through the Postfix server mx-fa-01. Postfix does not deliver to the Internet itself: it goes through its provider's authenticated SMTP relay, smtp.relais-kasbah.ma, port 587.

On Friday at 17:30, the provider enforced a new password for the fa-envoi account. Hind entered it in /etc/postfix/sasl_passwd from the provider's ticket (a sample value for the simulation, already in the file). Since then, nothing goes out; this morning, three clients are complaining.

Your mission: get all the queued messages moving again (none must be lost) and explain why Friday's change was not enough.