E-mail - Java 8 Recipes - page 796

How It Works
By using the setRecipients() method of the Message object, you can specify
multiple recipients on the same message. The setRecipients() method accepts an
array of Address objects. In this recipe, because you have a collection of strings, you
create the array as the size of the collection and create InternetAddress objects to
fill the array. Sending e-mails using multiple e-mail addresses (as opposed to individual
e-mails) is much more efficient because only one message is sent from your client to
the target mail servers. Each target mail server will then deliver to all recipients that it
has mailboxes for. For example, if you're sending to five different yahoo.com ac-
counts, the yahoo.com mail server will need to receive only one copy of the message
and it will deliver the message to all the yahoo.com recipients specified in the mes-
sage.
Tip If you want to send bulk messages, you might want to specify the Recipient
Type as BCC, so that the e-mail received doesn't show everyone else that is getting the
e-mail. To do so, specify Message.RecipientType.BCC in the setRecipi-
ents() method.
19-6. Checking E-Mail
Problem
You need to check if a new e-mail has arrived for a specified e-mail account.
Solution
You can use javax.mail.Store to connect, query, and retrieve messages from an
Internet Message Access Protocol (IMAP) e-mail account. For example, the following
code connects to an IMAP account, retrieves the last five messages from that IMAP ac-
count, and marks the messages as read .
Session session = Session.getDefaultInstance(properties,
null);