Well, that didn't work.   
I was able to send, and then I cannot send.  I tried many times today but, I get the following error:

POP3< +OK 0 0
POP3> QUIT
POP3< +OK Logging out.
* Account 'xxxxxxx@ruggedinbox.com': Connecting to SMTP server: ruggedinbox.com ...
SMTP< 220 csds.local ESMTP
ESMTP> EHLO localhost
ESMTP< 250-csds.local
ESMTP< 250-8BITMIME
ESMTP< 250-AUTH PLAIN LOGIN
ESMTP< 250-XCLIENT NAME HELO
ESMTP< 250-XFORWARD NAME ADDR PROTO HELO
ESMTP< 250-ENHANCEDSTATUSCODES
ESMTP< 250
ESMTP> STARTTLS
ESMTP< 500 5.5.1 Error: unknown command
** error occurred on SMTP session
*** Error occurred while sending the message:
500 5.5.1 Error: unknown command

I do not remember making any changes on my end, it just stopped sending.  I can receive without any trouble.
I see the error comes after STARTTLS.  What can I do to check my setting?  Here are the Send settings in Claws:

send:
generated message-id: yes
send account mail address in Message-ID: no
generate x-mailer header: no

SMTP authentication (SMTP AUTH): yes
Authentication method: Automatic
User ID: empty
Password: empty
Authenticate with POP3 before sending: no

SSL:
POP3:
Use SSL for POP3 connection

Send (SMTP):
Use STARTTLS command to start SSL session

Use non-blocking SSL: yes

Advanced:
SMTP port: no
POP3 port: no
Domain name: no
(everything is unchecked)

If you can think of anything that I can check, I would appreciate it!
Thank you!