Please use these publicly available possibilities whenever possible:
Most likely other people will also benefit from your question. There may also be users who are able to help, or willing to join a discussion, so not all the work is on us. Don't be selfish, think about our mail boxes they would be flooded if everybody would use just the email.
So, don't expect answers to emails which would well fit in the flickr forum or the issue tracker.
Only if this is not possible (no account does NOT count) you can reach us via e-mail: “mike” or “brother.john” @photivo.org.
Please check the Development page about current ideas and plans.