addressee
aircraft
airplane
bonus
circles
communicate
communication
correspondence
courier
deliver
deliverer
delivery
email
flat
glyph
icons
information
isolated
letter
logotype
mail
message
messaging
newsletter
outbound
outbox
outgoing
outlines
paper
paperplane
plane
post
round
send
sendmail
service
silhouette
solid
solidicon
solution
success
target
transfer
transport