Yahoo Mail SMTP Setup: App Password & Server Settings (2026 Guide)
Free Yahoo Mail. App Password mandatory. 3 minutes.
TL;DR
- check_circleYahoo SMTP server: smtp.mail.yahoo.com — port 465 (SSL/TLS) is the most reliable; port 587 (STARTTLS) is documented but flakier.
- check_circleYahoo requires an App Password — your regular Yahoo password will fail at the SMTP layer.
- check_circle2-Step Verification is required to generate App Passwords (Yahoo enforced this in 2022).
- check_circleDaily sending limit: 500 recipients / day, with hourly throttling at ~100/hour.
- check_circleYahoo accounts that have been inactive get aggressively throttled when reactivated — expect a warm-up period.
Connection settings
smtp.mail.yahoo.com465SSL/TLSYour full Yahoo email (you@yahoo.com)16-character App PasswordWhat you'll need
A Yahoo Mail account
Any @yahoo.com or country-specific Yahoo address (@yahoo.co.uk, @yahoo.de, etc.) uses the same SMTP host.
Two-Step Verification enabled
Yahoo no longer issues App Passwords without 2-Step Verification active. Turn it on first.
Yahoo Account Securityopen_in_newStep-by-step setup
- 1
Open Account Security
Sign in at login.yahoo.com/account/security. This is the only page from which you can manage 2-Step Verification and App Passwords.
Open Yahoo Account Securityopen_in_new - 2
Turn on 2-Step Verification
Click "Two-step verification" → "Get started" → follow the prompts. Yahoo will send a one-time code to your phone to confirm.
- 3
Generate an App Password
Back on the Account Security page, click "Generate and manage app passwords." Pick "Other app," name it something memorable (e.g. CodeOpx Mail), and click Generate.
lightbulbTip: Yahoo shows the 16-character password as four groups of 4 letters — copy it immediately. It's only shown once.
- 4
Use these SMTP server settings
Host: smtp.mail.yahoo.com · Port: 465 · Encryption: SSL/TLS · Username: your full Yahoo email · Password: the 16-character App Password (no spaces).
warningWatch out: Yahoo lists port 587 with STARTTLS as an alternative — it works but tends to disconnect mid-handshake more often than 465. Prefer 465.
- 5
Verify alias addresses if needed
If you want to send From: a Yahoo alias (e.g. you+filter@yahoo.com), Yahoo accepts plus-addressing automatically. To send from a completely different domain, you can't — use a custom domain provider like Zoho or Workspace.
Connect to CodeOpx Mail
Connect Yahoo Mail to CodeOpx in two minutes:
- 1Open SMTP configs
Dashboard → SMTP → "Add config" → choose Yahoo Mail. Host, port, and SSL toggle pre-fill.
- 2Paste credentials
Username: full Yahoo address. Password: the 16-char App Password.
- 3Test and save
Click "Test connection." A green check means Yahoo accepted the SMTP handshake. Now you're sending from Yahoo through CodeOpx's clean composer.
Common errors & fixes
535 5.7.0Authentication failed — invalid username or password
Yahoo rejected the credentials.
Fix: Regenerate the App Password (the old one may be revoked). Confirm 2-Step Verification is on. Make sure the username is your full email, not just the local part.
554 5.7.9Message not accepted — relay denied
Trying to send From: an address that isn't your real Yahoo account.
Fix: Set the From header to your actual Yahoo address. Yahoo strictly enforces sender alignment.
421 4.7.0Connection rate-limited
You're sending too fast for Yahoo's per-hour throttle.
Fix: Slow to ~50–80 messages/hour. Yahoo's documented daily cap is 500, but hourly throttling kicks in much earlier.
552 5.2.3Message exceeds size limit
Yahoo caps message size — including attachments — at 25 MB.
Fix: Compress attachments or host them externally and link.
Sending limits
Yahoo is the most aggressive of the free webmail providers when it comes to throttling. The 500/day cap is rarely the binding constraint — the per-hour throttle hits first for most users.
| Per-day sending | 500 recipients / day |
| Per-hour throttle | ~100 recipients / hour |
| Per-message recipients | 100 (combined To + CC + BCC) |
| Max message size | 25 MB including attachments |
| New account warm-up | First 30 days, sending is rate-limited automatically |
- lightbulbYahoo's spam filters are some of the strictest. A single complaint can hurt deliverability across all your sends — never send to addresses that haven't opted in.
- lightbulbFor volume above ~50/day, look at a transactional ESP. Yahoo SMTP is fine for personal/occasional sends, not bulk.
FAQ
Can I use my regular Yahoo password?
add
Not since 2022. Yahoo deprecated basic password authentication for IMAP and SMTP entirely. Apps that previously worked without an App Password now silently fail with 535 errors. You must generate an App Password.
Why does port 587 keep failing?
add
Yahoo's port-587 STARTTLS implementation is finicky — some clients disconnect mid-handshake. Port 465 with implicit SSL is rock-solid. Always start with 465.
Can I send from a Yahoo Plus alias?
add
Yes. Yahoo Mail Plus (paid) gives you up to 5 disposable aliases. Add them in Mail → Settings → Mailboxes → Aliases, then set the From header to the alias when sending.
Will Yahoo show my emails as 'unverified sender' to recipients?
add
If you send From: a non-Yahoo domain through Yahoo SMTP, Yahoo's gateway often rewrites the From to your real Yahoo address (sender rewriting). Recipients see your Yahoo identity, not the spoofed one — that's by design, to combat phishing.
Is Yahoo SMTP free?
add
Yes — Yahoo Mail is free and SMTP is included. You can also use it with Yahoo Mail Plus (~$3/month) for the same SMTP server, just with higher storage and ad-free reading.
Video tutorial
Watch: Yahoo SMTP App Password tutorials on YouTube
We curated a YouTube search of recent walkthroughs by independent creators. The official docs (linked below) remain the source of truth.
play_arrowWatch on YouTubeFurther reading
Related provider guides
Ready to send through yahoo?
Sign up for CodeOpx Mail, add this SMTP config, and you'll be sending tracked emails in under 5 minutes.