public void setMessageType(String messageType) {
        this.messageType = messageType;
    }
<p>
The SMS message type. Valid values are TRANSACTIONAL (for messages that are critical or time-sensitive, such as a
one-time passwords) and PROMOTIONAL (for messsages that aren't critical or time-sensitive, such as marketing
messages).
</p>

@param messageType
       The SMS message type. Valid values are TRANSACTIONAL (for messages that are critical or time-sensitive,
       such as a one-time passwords) and PROMOTIONAL (for messsages that aren't critical or time-sensitive, such
       as marketing messages).
@see MessageType
aws-java-sdk-pinpoint/src/main/java/com/amazonaws/services/pinpoint/model/JourneySMSMessage.java