Related Clues:
- Correspondence sans stamp
- It doesn't leave a paper trail?
- Virtual inbox fill
- It may come with attachments
- Target of some filters
- Texts at the keyboard
- Forward, perhaps
- Where all addresses include @
- What a server may serve
- Letters that can arrive at any time
- Write, these days
- Office communication
- Virtual inbox filler
- They may be sent with smileys
- Postal alternative