1. Start the Mail program.

If the Mail program isn’t already running, start it now.

2. Open the “Preferences” window.

Using the menu bar at the top of the screen, click Mail, then Preferences:

The preferences window will appear.

3. Choose the “Account Information” screen.

Navigate to the “Account Information” screen. To do this:

• Click Accounts (the blue "@" sign) along the top of the window if necessary.
• Click the address@example.com account in the left “Accounts” column if necessary.
• Click Account Information if necessary.

4. Verify the basic account settings.

The window should look like this:

Although the “Description”, “Full Name”, “Password” and “Outgoing Mail Server (SMTP)” may be different, everything else should be as shown above. In particular, these must be exactly right:

(If your window also has an “Alias” section, it doesn’t matter what those settings are.)

5. Verify the incoming advanced settings.

Now you should verify your outgoing port number. Click the "Advanced" tab.

The window should look like this:

In particular, check these:

Your “IMAP Path Prefix” may be blank; if so, that’s also okay.

You should usually make sure the Use SSL box is checked. Although this is not necessary to make your email work, it adds security. We also recommend that you do not check “Automatically detect and maintain account settings”, as it can cause Apple Mail to modify the settings.

6. Open the outgoing “Server Settings” window.

Go back to the "Account Information" tab. Click the menu that appears to the right of the words “Outgoing Mail Server (SMTP)” and choose Edit SMTP Server List..., like this:

(The “Edit SMTP Server List” option is labeled “Edit Server List” in some versions of Apple Mail. Also, the picture above shows the checked option as being labeled “address@example.com”, but don’t worry if it’s labeled something different: what matters is that you choose the option to edit the server list.)

The outgoing mail settings window will appear.

7. Verify the outgoing “Account Information”.

Verify that the “Account Information” tab looks like this:

In particular, check these:

(The “Description” doesn’t matter, but it’s helpful to use your email address to keep things clear if you use multiple outgoing mail servers.)

8. Verify the outgoing “Advanced Settings”.

Click the “Advanced” tab and verify that the window looks like this:

In particular, check these:

As with the incoming settings, we recommend checking the Use SSL box and not checking “Automatically detect and maintain account settings”.

9. Close both settings windows.

If everything looks okay, click OK to close the outgoing mail server settings window, then click the red close button in the upper-left corner of the Accounts window.