Setting up macOS Mail - Tahoe

In this guide, we will set up our one.com email account in the Mail application running macOS 26 Tahoe.

Step 1 - Open Mail and go to Settings

Open the Mail application via your Dock or in the Applications folder in Finder.

  1. Click Mail in the upper left corner.
  2. Select Settings in the menu.
Screenshot of the Mac Mail application with red numbered circles highlighting “Mail” and “Settings” in the menu.

Step 2 - Add new account

  1. In the preferences window, click the Accounts tab if it's not selected automatically.
  2. On the left side, you will see a list of all the existing email accounts in the Mail application. Click the small + icon in the bottom left corner of the list.

This will open up the Add account setup window.

Screenshot of the Mac Mail application with red numbered circles highlighting “Accounts” and the “+” icon.

Step 3 - Enter your email address

In the Add account setup window, enter your email address and click Continue. 

Screenshot of the Add Account setup window in the Mac Mail application with red arrows pointing to the “Enter your email address” field and the “Continue” button.

Step 4 - Choose Other Mail Account

Choose Other Mail Account in the list of email providers.

Screenshot of the pop-up window showing a list of email providers, with a red arrow pointing to “Other Mail Account.

Step 5 - Enter your account details

In the new pop-up window, enter the following:

  1. Name: the display name, which is the name your recipients will see when you're sending an email to them.
  2. Email Address: the email address you want to add.
  3. Password: the password you use when you're logging in to your one.com Webmail.
  4. Click Sign In.
Screenshot of the “Add a Mail Account” pop-up window showing account details, with a red arrow pointing to “Sign In.”

Step 6 - Enter your server settings

The Mail application will attempt to verify your details but fail after a few moments, showing you an error message "Unable to verify account name and password". This is normal and will not hinder you from continuing your setup.

Enter the following information:

  1. Email Address: Your email address.
  2. Username: Your email address.
  3. Password: Your email account password. (If not already filled in)
  4. Account Type: IMAP
  5. Incoming Mail Server: imap.one.com
  6. Outgoing Mail Server: send.one.com

Click Sign In.

Screenshot of the New Account screen showing incoming and outgoing mail server settings, with a red arrow pointing to “Sign In.”

Note: Weren’t you able to log in - Despite using the settings from above? Please check if you can log into Webmail. If you don't remember your email password, read our guide on how to change your email password.

Step 7 - Select apps to use

Next, you will be asked to Select the apps you want to use with this account. Here, ensure you only have selected Mail.

Click Done.

Screenshot of the pop-up window where you can select which apps to use, with a red arrow pointing to “Done.”

Step 8 - Setup email synchronisation

At this point, the Mail application will start downloading your emails and folders from our servers. Before we begin using the Mail application, setting up your email synchronisation is important to prevent emails from getting lost or moved to the wrong folder. This is particularly important if you wish to access the same email account on multiple devices, e.g. your computer and mobile devices.

By default, the Mail application will synchronise your Inbox, Drafts and custom folders automatically, but Sent, Spam and Trash folders will not be synchronised correctly.

To correct this, we need to go in and adjust some of our settings for our email account in the Mail application:

  1. Click on Mail in the menu at the top of the screen and select Settings.
  2. Click the Accounts tab in the Settings window.
  3. Select your email account in the left-hand menu.
  4. Once selected, click the Server Settings tab on the right-hand side of the window.
  5. Click the Advanced IMAP Settings button.
  6. In the small window that opens up, ensure that the IMAP Path Prefix is set to INBOX (in capital letters).
  7. Click OK to close the window.
Screenshot of the Server Settings tab in Mac Mail, with red numbered circles highlighting the “Mail” and “Settings” menus in the upper-left corner, “Accounts,” your email address, the “Server Settings” tab, and the “Advanced IMAP Settings” button.

Step 9 - Check Mailbox Behaviours

Finally, In the Preferences window, click the Mailbox Behaviours tab and ensure you have the following setup:

  • Drafts Mailbox is set to INBOX/Drafts
  • Sent Mailbox is set to INBOX/Sent
  • Junk Mailbox is set to INBOX/Spam
  • Bin Mailbox is set to INBOX/Trash

Once you select the folder, the Mail application will connect it and change the name by appending INBOX/ to it.

Note: Empty folders will not show up in the drop-down menu. If this is a brand new email account, log in to your email account via the one.com Webmail and place a draft email in the Drafts, Sent, Spam and Trash folders. This will allow the Mail application to see them and for you to select them in the drop-down menus.

Screenshot of the Mail Behaviours settings, with a red arrow pointing to “Mailbox Behaviours” and a red highlighted box showing the different mailboxes.

Step 10 - Done!

You did it! You can now use your one.com email account with the Mac Mail application on macOS 26 Tahoe.

Screenshot of the Mac Mail application showing the Inbox with example emails.

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