I've been testing this repeatedly but I can't get the welcome newsletter/email to send.
The test signups all show as waiting for a manual send but I can't send them manually either. I just get a failure message saying to check my outgoing email settings. However, the test email from within the settings pages works fine.
I found a couple of questions in the forum about this and have installed WP Crontrol but it doesn't appear to recognise the emails in the system and it doesn't appear to allow you to do much, either.