User Guide for SIP-T42G IP Phone542. Select an account and then press the Connect soft key to listen to voice mails.Message Waiting Indicator (MWI)The SIP-T42G IP phone supports MWI feature when receiving a new voice message. If someone leaves you avoice mail, you will receive a message waiting indicator. MWI will be indicated in three ways: a warning tone, anindicator message (including a voice mail icon) on the LCD screen, and the power indicator LED slow flashes red.This will be cleared when you retrieve all voice mails or delete them.