Preferred email / Send to userID

Description

Users have the option to specify their preferred E-Mail Address to receive emails to. Info is persisted in a simple NoSQL Database (e.g. Mongo). User is able to send an email to another user via /send @username. The e-mail is sent to the recipients preferred address.

Use Case

For some unknown reason you wish to send an e-mail to a person who you also could've messaged on Telegram directly...

CheckList

• command to set preffered e-mail address
• persistence of user preferences in a lightweight database
• option to send to usernames instead of e-mails, using their preferred mail