SMTP Outgoing Server Password Field Not Keying In Password

Good day, We assist clients that use Thunderbird Email Client with Outgoing Server. The issue is we cannot key in the Outgoing password it seems as if it only uses the Incoming Server password for the Outgoing server. Our clients use different Incoming and Outgoing Server details, how can we resolve this for the Outgoing Server to take a different password from the incoming server? Thanks.