Send email when user gets a new message

[stellarmagnet]

We used to send emails when new private messages were sent...but this doesn't seem to work anymore

May need some updates here?

https://github.com/spacedecentral/spacedecentral-network/tree/7d10af41960033a96b4465b7a91cfb8e6bba116d/app/views/application_mailer