I was testing Gibberbot to see if it works with Jitsi earlier and
found it's not possible to add a jit.si contact.
It seems this is because Gibberbot tries to send an e-mail to the
jit.si address to ask for permission to add the contact and as the
jit.si address isn't acutally an e-mail address, it's not possible for
this e-mail to be sent.
Adding a gmail.com contact worked fine though, as that can receive the
e-mail. My own domain address, hosted on gmail, worked fine as well.
I'm not sure there's anything that can be done about this, so it's
probably just something to make users aware of. Having said that, it's
obviously possible for Jitsi itself to add another jit.si contact, so
I guess it does that without needing to send an e-mail, so perhaps
Gibberbot can adopt the same technique. I realise this would be an
issue for the Gibberbot developers but wanted to check here first that
I'm not missing something.