It is not recommended to run nlserver command from console if instance is hosted by Adobe as adobe tech-ops team is the right team to run and execute these server level commands. You can reach out adobe support for such issue.
However to find out the which process are running/missing , you can see that from home page of console.
I agree to what Shrawan is saying here. Not recommended to start the processes using a workflow.
Using this approach, you will be able to restart the process only on the first server.
If you have multiple application servers and say you have MTA process running on server 1, 2 and 3. As per architecture the wfserver process will only be running on server1. So using a workflow, if you restart MTA the corresponding process on server1 will be started. Server2 and server3 will not undergo a restart.
Temporarily undelivered messages are subject to an automatic retry.
The central section of the Delivery tab for delivery parameters indicates how many retries should be performed the day after the delivery and the minimum delay between retries.
By default, five retries are scheduled for the first day of the delivery with a minimum interval of one hour spread out over the 24 hours of the day. One retry per day is programmed after that and until the delivery deadline, which is defined in the Validity tab.