Apple Mail Error: Cannot Send Message Using the Server

Apple Mail is a popular email client with an 11.5 percent market share and leads the Desktop market with a 58.9 percent share.

It helps iOS and Mac users connect to popular email providers like Gmail, Yahoo Mail, iCloud Mail, Outlook, and more.

Apple Mail users can:

  • Can configure the application to receive all their email accounts in one list
  • File emails into folders
  • Automatically append a signature to outgoing emails

The Mail can also integrate with your contact list, calendar, map and other applications, helping you stay organized.

While sending a message via the client, you might receive any  of these messages (or probably a related message) :

  • Cannot send a message using the server [server address]
  • The sender address [your email address] was rejected by the server [server address]

This article guides you on the causes and how to fix them.

Causes of Apple Mail Error and How To Fix It

Apple Mail may not be able able to send emails if any of these three issues occur:

  • If you change your outgoing mail
  • Your mail preference file failing to update changes
  • You have a corrupted mail preference file

Let’s quickly take a look at them and how to resolve the errors.

Changed Outgoing Mail Setting 

Email service providers often upgrade their mail servers to protect them against malicious attacks.

The upgrade might cause the Mail settings to misalign with the upgraded server settings, preventing you from sending messages with your Apple Mail.

But you could fix this by configuring your outgoing mail settings, and here’s how :

  1. Open Apple Mail to get started. 
  2. Select Preferences from the menu.
  3. Click the Accounts button in the Mail preferences window.
  4. Select the email account you couldn’t send messages from.
  5. Click the Server Settings or Account Information tabs to find the incoming and outgoing mail settings pane. You could get to the pane by clicking the Server Settings tab in some versions or through the Account Information tab in other versions.
  6. Select Edit SMTP Server List in the Outgoing Mail Server (SMTP) section, from the dropdown menu labeled Outgoing Mail Server (SMTP) or Accounts, of course, depending on your Apple Mail’s version.
  7. Step 5 displays a list of all the SMTP servers set up for the various email accounts added to your Apple Mail. 
  8. Select the server the email account uses.
  9. Click the Server Settings or Account Information tab. 
  10. Make sure the server or hostname is correct. 
  11. Remove duplicate servers, if there are multiple servers with the same  name.
  12. Click the Advanced tab, and ensure all the fields match the setting provided by your mail service provider.
  13. If available, place a checkmark to Use Secure Sockets Layer (SSL).
  14. Select Password as your authentication type.
  15. Ensure your username and password matches your email address and password, respectively – otherwise, make the changes.
  16. Click OK.

That’s it.

Mail Preference File Failing to Update Changes

Apple Mail could still fail to send and receive your messages even when you configured the settings correctly. In this case, the Mail Preference File becomes the main culprit.

Apple Mail error could occur when the app fails to update changes, thereby preventing you from saving updates to your Mail settings.

The update failure could be due to a permission issue that prevents Apple Mail from writing data to its preference file, and resetting the file could resolve this.

Follow these quick steps to get back on track.

Launch the ‘Finder Search Window’ on your Mac device and open the ‘Go’ menu to select ‘Go to Folder…’

Apple Mail Error: Cannot Send Message Using the Server

Type ~/Library/Preferences in the text box and click Go to open the folder.

Apple Mail Error: Cannot Send Message Using the Server

Look for the file ‘’ in the folder and delete it. You could click and drag the file into the trash icon on your desktop to delete it.

Apple Mail Error: Cannot Send Message Using the Server

Restart Apple Mail. 

The application will run a setup wizard as if you’re launching it for the first time. Re-enter all your email settings again following the step earlier described above.

Note: you could consider backing up your messages before resetting your preference file. You might lose them after resetting the file.

Corrupted Mail Preference File

A corrupted mail preference file makes the file or section unusable, which often causes an Apple Mail error. Reset the file to resolve the issue and re-enter your email settings to restore functionality.

Wrapping It Up

Changed outgoing email settings, mail preference file not updating, and corrupted mail preference file are some of the major causes of the Apple Mail error. The error could be a major inconvenience, especially if you rely on emails to do your jobs. 

Thankfully, the steps outlined in this article help resolve the issue quickly and effortlessly, and you can always contact our support team if you need further assistance.



Working in the web hosting industry for over 13 years, Rado has inevitably got some insight into the industry. A digital marketer by education, Rado is always putting himself in the client's shoes, trying to see what's best for THEM first. A man of the fine detail, you can often find him spending 10+ minutes wondering over a missing comma or slightly skewed design.

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