Is there anything waiting on the distribution queues? (WRKDSTQ).
Try querying the distribution log to see if there are any messages regarding your distributions (QRYDST).
SNDDST sends the distribution, but I assume you’re actually wanting SMTP e-mail rather than a SNA distribution. If so, please make sure you describe what you need. SNDDST isn’t intended as a SMTP client, although it is possible to route some distributions over to SMTP. There is very little relationship at all between CFGTCP and SNDDST.
If that’s what you actually need, you probably should be using appropriate tools.