Perlbug cannot know if the mail delivery happened to the final recipient. Perlbug hands off the mail to the local mail transfer agent (MTA), which hopefully forwards that mail to the next link in the chain. If sendmail (or whatever) is not configured to send outbound mail, hopefully it will send mail to root after the mail has lingered in its undeliverable state for some time. I don't know how Ubuntu handles its maili setup.

Thanks for all the tips.

Welcome

I just created the Bitcard accound and added the bug manually. I thought at first that "Bitcard" was some private company. It's all rather user unfriendly

Why not to just use the friendly interface you just thanked me for explaining?

I started perlbug from Ubuntu Linux, and how would I know whether it is misconfigured to send e-mails if it reports "OK" at the end?

perlbug (and other programs using your mail system) have no control over what your mail system does after they submit an email to it, and they no reasonable way to query it.

I haven't used perlbug, but from the discussion (and from the source :-)) it might help to simply change the text from "Message sent" to "Message has been handed over to your mail system". For anyone who is capable of using perlbug in the first place, that should be sufficient. Rats! Now I have to find out how to make a pull request :-)

Update: https://rt.perl.org/Public/Bug/Display.html?id=128180

it might help to simply change the text from "Message sent" to "Message has been handed over to your mail system"

That's just a noisy way of saying the same thing. Sending an email is a chain of handoffs, and there's never a guarantee that a sent email will reach its target.