Set up to send texts using Messages on Mac
Use iMessage to send unlimited messages to friends who use iPhone, iPad, iPod touch and Mac.
If you have an iPhone with iOS 8.1 or later, you can also send SMS messages to any mobile phone from your Mac. See Set up iPhone to get SMS texts on Mac.
Set up to send text messages with iMessage
In the Messages app
on your Mac, choose Messages > Preferences, then click iMessage.Enter your Apple ID and password, then click Next.
If you’ve made purchases from the iTunes Store or App Store or signed in to iCloud, you already have an Apple ID. If you don’t have an Apple ID, you can create one in Messages.
Make sure the Apple ID is the same Apple ID you’re using on your other devices. See the Apple Support article Use Continuity to connect your Mac, iPhone, iPad, iPod touch, and Apple Watch.
If you forgot your password or Apple ID, go to your Apple ID account page, select “Forgot Apple ID or password?” then follow the instructions.
After signing in, select the following options:
Store your messages in iCloud: Select “Enable Messages in iCloud”. See Use Messages in iCloud.
You can be reached for messages at: Select the email addresses or phone numbers you want people to be able to use to send you texts on this Mac using iMessage.
See the Apple Support article Add or remove your phone number in Messages or FaceTime.
Send read receipts: If you select this, people who send you messages will see when you’ve read them.
You can also send read receipts for a conversation only.
Start new conversations from: Choose the email address or phone number that you want to use for starting new conversations.
This option is only available if you have more than one email address or phone number listed under “You can be reached for messages at”.
Stop using iMessage
If you don’t want to see messages on your Mac, you can make iMessage inactive or just sign out.
In the Messages app
on your Mac, choose Messages > Preferences, click iMessage, then select Settings.Do one of the following:
Make iMessage inactive: Unselect “Enable this account.” When you make iMessage inactive, your status is displayed as Offline.
Note: If you just want to stop receiving text messages sent to your phone number, unselect the phone number under “You can be reached for messages at.” See the Apple Support article Add or remove your phone number in Messages or FaceTime.
Sign out of iMessage: Select Sign Out, then confirm that you want to sign out. When you sign out of iMessage, you no longer receive messages through that account.