Each channel in AirSend has an email address.
When you initially create a channel, the email address appears in the messaging section.
When you invite someone to join a channel, they receive the email address in a message.
When you or another user sends a message to the email address with a file included in it, the file appears in the messaging section and in the attachments folder of the Files tab or Files section.
When you receive an email message from an AirSend channel and reply to it, the reply address is also the channel's email: