Today I can't reply to alsa-user anymore. I'm an unknown user, but I can
log in and change settings. Mail delivery was disabled, but actually I
still got mails from alsa-user. I changed my address to no avail, I
subscribed by another address, to know avail. The users are unknown,
alternatively the recipient domain is not specified, at least the error
message claims this ;).
Then I noticed that after changing my email address for my old alsa-user
account the confirmation mails are for alsa-devel, instead of
alsa-user, but they take affect for the alsa-user account, if I want to
log in, I need to use the new address.