Board Thread:Support Requests - Community Management/@comment-251883-20140531064327/@comment-3026053-20140531190720

Also, even if the email notification function is on, that just sends you a mail that you have received a message on a certain wiki. That does not enable you to mail the user in question in case you wanted to discuss something privately -thus in another place than the message walls/talk pages. Chat/IRC could be used as a substitute in some cases, but that obviously doesn't work for inactive users or users living in totally different timezones.

An alternative option is to create a secondary email address yourself with your username on a provider of your choice, but that obviously isn't as effective as the user mailfunction as it can only be used by those who know your mailaddress.