Submitted "send test" form but nothing happened

Trying to figure out why this fails and discovered the "send test" form doesn't work unless Sendgrid is already set as the site mailer.

1) Would be nice if, at minimum, the form spelled that out. Better yet, the form could detect how the site mailer was set up, and set a warning message if we can predict that the form will do nothing.

2) Would be even better if the form bypassed the site mailer settings, and just called the sendgrid mailer directly, so that we can know in advance of deployment whether our configuration will work.

Derp.

Mailsafety module was enabled and preventing emails.