It's unclear to me. It's also hard to have something recognizable, but a even just a dynamic URL on the main website: https://www.ponymessenger.com/contactme/<u

It's unclear to me. It's also hard to have something recognizable, but a even just a dynamic URL on the main website: https://www.ponymessenger.com/contactme/<username> https://www.ponymessenger.com/contactme/<username> where a user can have an easy to customize message, or even a pre-done one "Hi I'm using pony for my inbox, you can send me a message using pony by doing XXX,". That way in slides, mails, ... I can just put "contact me at URL". Maybe also a mail server bridge ? If So write to <user>@ponymessenger.com it reply with "You message will be once a day, you can edit and cancel, by clicking this link".