SMTP · App Password

How to connect
Yahoo Mail.

Generate a Yahoo app password and enter Yahoo’s outgoing mail settings.

Connection preview. You can read this guide and save a mailbox for later. Live authorization and warm-up remain off. Do not enter real credentials while the connection form is disabled.

Before you start

  • Access to the Yahoo account that owns the address.
  • Availability of Yahoo’s third-party app password feature.

Step-by-step setup

  1. Generate a Yahoo app password

    Open Yahoo Account Security and find the app password option. Give the password a recognizable app name and copy the generated value for this connection.

  2. Keep your full Yahoo address ready

    Use the full email address for authentication, including the part after @. The app password goes in the SMTP password field, not your regular sign-in password.

  3. Choose Other provider in MailboxWarm

    Open Mailboxes → Add mailbox, choose Other provider, and enter your sending email address. Named SMTP services all use this same Other provider connection option.

  4. Enter the connection details

    When connections are enabled, enter the SMTP values listed below. Choose Test & connect. MailboxWarm checks authentication and the encrypted connection without sending a message.

Connection settings

Match these values to the fields in MailboxWarm. Keep passwords and keys private.

Connection option
Other provider
SMTP host
smtp.mail.yahoo.com
Encryption / port
SSL / TLS / 465
SMTP username
Your full Yahoo email address
SMTP password
Yahoo app password

SMTP sends; it does not read your inbox. This connection does not include IMAP access to your mailbox. Placement and rescue activity concern the controlled seed inboxes receiving warm-up messages. Provider-specific compatibility still needs live validation.

Check the result

In today’s preview, expect Mailbox saved for later. When connections are enabled, a successful check shows Mailbox connected, with warming still paused. A failed connection check is not proof of delivery or a reason to add the same mailbox again.

Once live warming is available, choose the mailbox’s plan and schedule before starting. Connecting alone does not begin warm-up, and your provider’s sending limits still apply.

Open setup preview

Troubleshooting

Yahoo cannot generate an app password

Check Yahoo’s account help. If Yahoo does not offer the credential for your account, this password-based connection cannot proceed.

Authentication fails

Use the generated app password and full Yahoo address. Confirm that port 465 is paired with SSL / TLS.

Provider resources

Provider menus and account policies can change. Use their official documentation for the latest requirements.

Settings reviewed September 12, 2026 · Documentation review, not a live connection test.