With Mercury messenger you can send email and text to friends in your contact list or send private messages to another Alexa device. All you need to do is to link your account with the Mercury platform and start to populate your contact list. To send an email to a contact you should create a contact providing an email address. To send a text your friends' contact should have a valid mobile phone number. If you want to send a private message, ask your friend to add the Mercury message skill on his/her Alexa device and to give you the email used to link the account with Mercury. You can retrieve the email you used with the command "Alexa, ask Mercury messenger who am I".
“Alexa, ask mercury messenger to send a text to emily”