Adding a mailbox to Outlook means connecting a second email address to the same inbox

You can add another email account to Outlook without switching between separate inboxes. Outlook lets you view, send, and receive mail from multiple addresses in one place. The process takes about five minutes and works whether your second account is a Microsoft account (Outlook.com, Hotmail, Live.com) or an account from another provider like Gmail, Yahoo, or your work email.

The steps differ slightly depending on whether you are using Outlook on the web, Outlook desktop, or Outlook on your phone. This guide covers the desktop version for Windows and Mac, which is where most people manage multiple accounts.

Key Takeaways

  • You can add a second email account to Outlook desktop by going to File > Add Account and entering the email address and password.
  • Microsoft accounts (Outlook.com, Hotmail) connect automatically; other providers may require you to allow "less find apps" or generate an app-specific password.
  • Once added, you can switch between accounts in the folder pane on the left side of Outlook, or set one as your default sending address.
  • If Outlook cannot connect automatically, you may need to enter your mail server settings manually or check your email provider's security settings.

Adding a Microsoft account or Outlook.com address

If your second account is an Outlook.com, Hotmail.com, or Live.com address, the connection is straightforward. Open Outlook on your computer, click File in the top left, then select Add Account. Type in your email address and click Connect. Outlook will ask you to sign in with your Microsoft password. Once you do, the account connects automatically and appears in your folder list on the left.

You do not need to enter server settings or change security options for Microsoft accounts. The account will sync your inbox, calendar, contacts, and other folders within a few minutes. If you have two-factor authentication turned on for that Microsoft account, you will need to complete that step during sign-in.

Adding Gmail, Yahoo, or other email providers

Non-Microsoft accounts require an extra step because those providers do not allow Outlook to connect using your regular password. Instead, you generate a one-time app password that Outlook uses to access your account without storing your actual password.

For Gmail: Go to myaccount.google.com, click Security on the left, scroll down to App passwords, and select Mail and Windows (or your device type). Google generates a 16-character password. Copy it, then return to Outlook, click File > Add Account, enter your Gmail address, and paste the app password when prompted.

For Yahoo Mail: Sign into your Yahoo account, go to Account Security, and click Generate app password. Select Mail and Windows. Copy the password, then add the account to Outlook using the same File > Add Account route and paste the app password.

For work email or other providers: Ask your IT department or email provider whether they support app passwords. If they do, follow their instructions to generate one. If they do not, you may need to enter your mail server settings manually (see the section below).

Entering server settings manually

If Outlook cannot connect automatically and your provider does not offer app passwords, you can enter the mail server details yourself. When Outlook shows a connection error, click Advanced Options and select Let me set up my account manually. You will see fields for incoming and outgoing server addresses, port numbers, and encryption type.

Your email provider's support page lists these settings. For example, Gmail's incoming server is imap.gmail.com on port 993 with SSL encryption; the outgoing server is smtp.gmail.com on port 587 with TLS encryption. Enter these exactly as your provider specifies. If you are unsure, contact your provider's support team or check their help documentation.

After you enter the settings, Outlook tests the connection. If it succeeds, the account is added. If it fails, double-check that you copied the settings correctly, including capitalization and port numbers.

Switching between accounts and setting a default sender

Once both accounts are added, you will see them listed in the folder pane on the left side of Outlook. Click on an account name to view its inbox. When you compose a new email, Outlook defaults to sending from whichever account you were viewing last. To change the sender for a specific email, click the From field in the compose window and select the account you want to send from.

If you want one account to be your default sender for all new emails, go to File > Options > Mail (Windows) or Outlook > Preferences > Accounts (Mac). Find the account you want to use by default and look for a setting labeled "Set as default account" or similar. This ensures new emails send from that address unless you manually change it.

Troubleshooting connection problems

If Outlook cannot connect to your second account, the most common cause is a password or security setting issue. First, verify that you are using the correct password by signing into the email account directly in a web browser. If you can log in on the web but not in Outlook, your email provider likely requires an app password or has blocked Outlook for security reasons.

Check your email provider's security settings. Gmail, Yahoo, and others may show a notification that Outlook tried to connect and was blocked. These notifications usually include a link to allow the connection. Click that link, then try adding the account to Outlook again. If you still see an error, try removing the account from Outlook and adding it again from scratch — sometimes the connection succeeds on a second attempt.

For work email accounts, contact your IT department. They may need to enable IMAP or POP3 access, adjust firewall settings, or provide you with specific server addresses that differ from the public ones.

Managing multiple accounts and staying organized

With two or more accounts in Outlook, you can create rules to automatically sort incoming mail by account. Go to File > Manage Rules & Alerts (Windows) or Tools > Rules (Mac), then click New Rule. You can set up a rule that moves all emails from your second account into a specific folder, or flags them with a color so they stand out in your inbox.

You can also create separate signatures for each account. Go to File > Options > Mail > Signatures (Windows) or Outlook > Preferences > Signatures (Mac), create a new signature for each account, and assign it to the correct sender address. This way, emails from your work account automatically sign with your work signature, and emails from your personal account use your personal signature.

Frequently Asked Questions

Can I add more than two email accounts to Outlook?

Yes. Outlook supports as many accounts as you want to add. Each one appears in your folder list, and you can switch between them by clicking the account name. The process is the same for the third, fourth, or fifth account as it is for the second.

Will adding a second account delete emails from my first account?

No. Adding another account does not affect your existing inbox or any emails already in Outlook. Both accounts remain separate in the folder pane, and you can view either one without changing the other.

What if I forget which account I am currently viewing?

Look at the folder pane on the left side of Outlook. The account name appears at the top of the folder list, and the currently selected account is highlighted. You can also check the From field in a compose window to see which account you are about to send from.

Can I remove an account from Outlook without deleting it?

Yes. Right-click the account name in the folder pane and select Remove Account (or Delete Account on Mac). This removes it from Outlook but does not delete the actual email account or any messages. You can add it back later if you need to.

Why does Outlook keep asking me to re-enter my password?

This usually means your password has expired, your provider has changed security settings, or Outlook lost the saved credentials. Try removing the account and adding it again. If the problem continues, check whether your email provider requires an app password instead of your regular password, or contact their support team.