AASTRA DT4x2 for BusinessPhone User Guide EN - Manual (Page 66)

Messages
BusinessPhone – Cordless DT412/DT422/DT432 66
To delete a message:
Delete
Press (see display).
Delete message?
is shown in the display.
Yes Press to delete the message (see display).
If you get a text message with a request for answer, the text
Acknowledge
is added to the message. Use the Soft keys to do a
positive or negative acknowledgement.
Note: The option Delete
is not available for a message
with request for answer. An unacknowledged message can
only be deleted from the message list.
To reply to an incoming text message:
Reply Press (see display). å
Send Enter the message text and press (see display).
Sending
is displayed as a confirmation of the transfer.