https://github.com/crisward/imap
IMAP client library for Crystal
require "imap"
imap = Imap::Client.new(host: "imap.gmail.com", port: 993, username: "email@gmail.com", password: "*******")
mailboxes = imap.get_mailboxes
if mailboxes.size > 0
mailbox = mailboxes[0]
imap.set_mailbox(mailbox)
message_count = imap.get_message_count
puts "There are #{message_count} message in #{mailbox}"
end
imap.close