AASTRA DT590 for MX-ONE User Guide EN - Manual (Page 73)

73 DT590
Messages
Send a text message (SMS) ¾
Press.
The Phonebook tab is marked. º
Navigate to Messages.
Use Navigate key to select Send and then New. ¿ Ь Ы
Write the text and press.
How to write text, see section “ Write text and numbers ” on
page 44 ¿ Ь Ы
Enter the destination number and press.
You can dial the number, or use the Phone book. The message is
sent.