The page here https://www.emailarchitect.net/easendmail/ex/d/7.aspx explains how to send emails using the queue.

I couldn't make the example work using the exact code on that page because in the line

SendMailToQueue expected a string parameter (Formal parameter name 'Instant') to be passed to it.

Not knowing what that was, I simply passed the empty string and the email queuing and sending worked fine.

But what is the parameter Instant supposed to be used for and is there anything special that I should be setting it to?

Yes I did look at those links, hence my post.
The only explanation for the Paramater is


and the example shows simply


But how do I know what string vaule I need to pass for any particular installation?
How do I know what my "EASendMail Service instance" is?

Passing an empty string to SendMailToQueueEx seems to work, so what is the difference detween doing that and passing some other string ?

Ah, OK I understand now, thank you.