If you’re connected to WI-FI on your Mac, you can send and receive iMessage between other Apple contacts. Since your Mac doesn’t have a cellular plan and isn’t assigned to a cellular number, you can only send iMessages and not text messages with your Mac.

Since you can’t send regular text messages and you can only send messages using the internet, this can lead to a whole host of problems. Internet connection isn’t always reliable, and it can always cause problems when using online services like iMessage.

If you can see a red exclamation mark next to your iMessage and under the exclamation mark, there’s a message saying Not Delivered, this means that the message didn’t send, and the recipient didn’t receive any messages. Although there’s an option for you to resend this message, there may be an underlying issue that still stops the messages from sending.

The Reason iMessage Won’t Send

The main reason why your iMessage won’t send is that there’s a problem with keychain access that’s stopping iMessage from sending your message even when you’re connected to WI-FI. You’ll need to login into Keychain Access to troubleshoot the problem with your Mac.

If you want to resent the message: click on exclamation point and you’ll see a pop up saying, “Your message could not be sent.” > Click Try Again. If the message didn’t send after trying again, you’ll need to troubleshoot the problem.

1. Unlock Keychain Login

Keychain Access on your Mac is password management system. The keychain can store all your passwords for applications, or even sensitive information that’s unrelated to your Mac PC. Keychain Access can affect the way you use apps and sometimes you may need to log into Keychain in order to use iMessage properly.

1. Open Keychain Access.

2. Click File.

3. Lock Keychain Login.unlock keychain

4. Click File and Unlock Keychain Login.

5. Enter your Admin password. From here, you should be able to send messages using iMessage because your Keychain Access has been restarted.

If this didn’t work for you, there may be a corrupted file within Keychain access that stops you from sending iMessages.

2. Delete Corrupted Files

To delete corrupted files in Keychain Access:

1. Open Keychain Access.

2. Search for com.apple.facetime: registrationV1.

3. Delete it. From here, you can resend the iMessage and it should send.

4. Check if both Devices are Using the Same Account.

On your Mac, you need to be using the same account for iMessage that you’re using on your iPhone.

On your Mac:

1. Go to Messages.

2. Click on Preferences.

3. Select Accounts.

4. Click iMessage Account.

On your iPhone:

1. Go to Settings.

2. Click on Messages. Check if send and receive are the same accounts.

3. Force Restart Mac

If the problem is being caused by your Mac itself, a force restart usually fixes the problem within the software that stops you from sending iMessages.

To force restart your Mac, hold Control + Command while pressing the Power button. This combination will force restart your Mac. Once your Mac turns on, check if you can still send messages using iMessage.

4. Turn Off Firewall

Although firewalls are meant to protect your Mac from Malware, it can also stop you from performing certain actions on your Mac because your firewalls may detect it as something harmful even when it’s not.

To turn off the firewall on Mac:

1. Choose System Preferences in the Apple menu.

2. Click on Security or Security & Privacy.

3. Click the Firewall.

turn off firewall mac

4. Click Turn Off Firewall.