Sina Mail (@sina.com / @sina.cn) · Client Auth Code
Sina Mail (@sina.com / @sina.cn / @2008.sina.com) is one of China's three classic portal mailboxes (alongside NetEase and Sohu). Connecting it to Laifaxin takes 2 steps:
| Step | What | Required |
|---|---|---|
| 1 Enable IMAP/SMTP service in webmail | Disabled by default — turn it on at webmail [Settings → Client POP/IMAP/SMTP] | Yes |
| 2 SMS verification to generate a 16-char client auth code | For Laifaxin (not the login password) | Yes |
When binding, paste the 16-char client auth code into the password field (not your Sina login password) — otherwise it fails 100% of the time.
Sina Mail strictly requires a client auth code for third-party clients — using the login password returns 535 Authentication failed.
The auth code is a 16-char standalone password, far more secure than the login password (a leak doesn't affect the main account).
1. Server Settings
| Type | Server | SSL Port |
|---|---|---|
| IMAP (incoming) | imap.sina.com | 993 |
| SMTP (outgoing) | smtp.sina.com | 465 |
Encryption: SSL / TLS
Sina's free mailboxes @sina.com / @sina.cn / @2008.sina.com use the same servers, and setup is identical.
VIP mailbox @vip.sina.com uses different servers — see the VIP-specific guide.
2. Get the Client Auth Code
2.1 Settings → Client POP/IMAP/SMTP
Sign in to Sina Mail webmail → top-right Settings → Client POP/IMAP/SMTP tab:
Scroll to IMAP4/SMTP service → set service status to On:
2.2 SMS verification
When enabling the service, the system requires SMS verification. Enter your bound mobile number → enter the SMS code → confirm:
2.3 Get and copy the 16-char client auth code
After verification, the system displays a 16-char client auth code → copy and save immediately:
You can't see it again after closing the dialog. Immediately save it to a password manager (1Password / Bitwarden).
If lost, you can only redo the whole flow to regenerate.
3. Bind in Laifaxin
Go to Laifaxin Email Accounts and add your Sina email:
| Field | What to fill |
|---|---|
| Email address | your@sina.com or @sina.cn / @2008.sina.com |
| Password | Paste the client auth code (NOT the login password!) |
| IMAP server | imap.sina.com · port 993 · SSL |
| SMTP server | smtp.sina.com · port 465 · SSL |
After binding, turn on email sync + notifications (see Check New Emails).
Common Pitfalls
| Pitfall | Consequence | How to avoid |
|---|---|---|
| Using Sina login password | 535 Authentication failed | Must use the 16-char client auth code |
| IMAP/SMTP service not enabled | Binding fails (disabled by default) | First go to Settings → Client POP/IMAP/SMTP and enable the service |
| Phone not bound / number changed without update | Can't receive the SMS code | First update the bound phone in Sina Mail's Account Security |
| Auth code generated but not copied | Gone after closing the dialog | Copy immediately to a password manager |
| Heavy mass sending via Sina | Rate-limited or temporarily blocked within 24h | Personal mailboxes are 1-on-1 only; bulk → premium channels |
| Password changed / service toggled / auth code deleted | Laifaxin uses an old code, sending fails | Regenerate the auth code, then update it in Laifaxin |
| Sharing one auth code across clients | Hard to revoke individually | Each client should have its own auth code |
FAQ
Q1 · Why use an auth code instead of the login password?
Security policy. Sina Mail does not allow third-party clients to use the login password. Reasons:
| Aspect | Main login password | Client auth code |
|---|---|---|
| Use | Sign in to Sina webmail | Used by third-party clients |
| Quantity | 1 | Multiple |
| Revocation | Change password = all apps disconnect | Can revoke individually without affecting the main account |
| Leak risk | Main account at risk | Only that one app affected |
| Sina policy | Not allowed for third-party clients | Mandatory |
Q2 · Does changing my phone number affect auth code retrieval?
Yes. Getting an auth code requires an SMS code to the bound phone. If you change numbers:
| Step | Action |
|---|---|
| 1 | Go to Sina Mail webmail → Account Security Settings |
| 2 | Update the bound phone number (requires the old phone's SMS + mailbox password) |
| 3 | Use the new phone to regenerate the client auth code |
Q3 · What's the difference between Sina's 3 free suffixes?
| Suffix | Launched | Trait |
|---|---|---|
@sina.com | Earliest, best-known | Iconic Chinese portal mailbox |
@sina.cn | Launched later | Backup once .com filled up |
@2008.sina.com | 2008 Beijing Olympics commemorative | Historic significance |
→ Same servers and backend; setup is identical.
Q4 · How many emails can Sina Mail send per day?
Sina doesn't publish a hard limit, but heavy sending is strongly discouraged:
| Phase | Daily volume | Notes |
|---|---|---|
| Week 1 (new bind) | Start at 50 | 5–10 minute intervals |
| Weeks 2–4 | 100–200 | Watch for anomalies |
| Stable | Max 300 | Don't hit the cap |
→ Never "mass blast" at any stage! Mass blasting = 100% triggers anti-spam.
Truly need bulk sending? Use premium channels:
- Doesn't touch your Sina, no risk of ban
- ¥0.007 per email, system auto-throttles
Q5 · Do I need a VPN for Sina Mail?
No. Sina Mail is a domestic Chinese service with stable access from within China.
Q6 · Is Sina Mail good for foreign trade?
| Scenario | Fit | Notes |
|---|---|---|
| 1-on-1 client follow-up | Low fit | Overseas customers have low trust in @sina.com |
| Inquiry replies | Low fit | Same as above |
| Bulk cold outreach | Not suitable | Likely to land in overseas spam folders |
| Multi-touch auto follow-up | Not suitable | Use smart sequence + premium channels |
Verdict: Sina Mail works for domestic Chinese business; for foreign trade, use Gmail / Outlook or a custom-domain enterprise mailbox.
Q7 · Lost the auth code or want a new one?
| Step | Action |
|---|---|
| 1 | Sina webmail Settings → Client POP/IMAP/SMTP |
| 2 | Find the IMAP4/SMTP service section → regenerate the auth code (SMS verification) |
| 3 | In Laifaxin Email Accounts, update the password and save |
Learning Tips
| Topic | Advice |
|---|---|
| Separate auth code per client | One for Laifaxin / one for Foxmail / one for Thunderbird — enables precise revocation |
| Safeguard the auth code | Use a password manager (1Password / Bitwarden); lost = regenerate |
| Periodic review | Quarterly check Sina Mail Settings for active clients and disable unused ones |
| Keep phone number bound | Update immediately if you switch numbers, otherwise regen is blocked |
| Pair with Laifaxin features | After binding, try email tracking / templates / smart sequence |
| Use premium channels for bulk | Bulk doesn't use Sina — use premium channels |
| International mailboxes for foreign trade | For real foreign trade, use Gmail / Outlook or a custom-domain enterprise mailbox |
Related Features
| Topic | Link | Description |
|---|---|---|
| Email account setup | email-account | Binding flow + error code troubleshooting |
| Common personal mailboxes | 100-gerenyouxiang-personal-mailbox | 16 mailbox quick-reference table |
| Tencent QQ Mail (@qq.com) | 106-tengxun-qqyouxiang-tencent-personal-email | Also uses an auth code |
| NetEase Mail (@163.com) | 107-wangyi-163youxiang-netease-personal-email | Also uses an auth code |
| Sohu Mail (@sohu.com) | 105-souhu-sohuyouxiang-sohu-personal-email | Same idea (called "independent password") |
| Google Mail (@gmail.com) | 101-guge-gmailyouxiang-google-personal-email | App-specific password (same idea) |
| Check new emails | check-new-emails | Enable sync + notifications after binding |
| Mass sending | email-mass-sending | Bulk: use premium channels |
Scroll to the bottom of this page, scan the customer-service WeChat QR (already in the footer) for 1-on-1 help — instant response during business hours, first thing next morning otherwise.
About Sina Mail (@sina.com / @sina.cn)
What is Sina Mail?
Sina Mail is offered by Sina Corp and is one of China's earliest free webmail services, sitting alongside NetEase Mail and Sohu Mail as the three classic Chinese portal mailboxes. It integrates with the Sina Weibo ecosystem and offers large attachments, mail archiving, and intelligent anti-spam.
Main Sina Mail brands:
| Suffix | Type | Trait |
|---|---|---|
@sina.com | Free | Earliest and best-known; iconic portal mailbox |
@sina.cn | Free | Backup domain once .com filled up |
@2008.sina.com | Free | Beijing Olympics commemorative |
@vip.sina.com | VIP (paid) | Large storage + strong anti-spam + dedicated support |
Why does Sina Mail require an auth code?
Sina security policy:
- Sina Mail follows the mainstream Chinese mailbox approach: an auth-code mechanism for third-party clients
- Currently, third-party clients must use a client auth code for IMAP/SMTP — login passwords don't work
Naming comparison (Sina vs others):
| Mailbox | Name |
|---|---|
| Sina / Tencent / China Mobile | Auth code / Client auth code |
| NetEase | Client auth code |
| Sohu | Independent password |
| Google / Yahoo / Microsoft | App password / App-specific password |
→ All are dedicated passwords for third-party clients, safer than login passwords.
Is Sina Mail good for foreign trade?
1-on-1 follow-up / inquiry replies Low fit:
- Overseas customers have low trust in domestic Chinese portal mailboxes like
@sina.com - More likely than Gmail / Outlook to be flagged as suspicious by overseas mail providers
- Deliverability is relatively poor
Bulk cold outreach Not suitable at all:
- Overseas mail providers often route
@sina.comstraight to spam - Triggers anti-spam rules
Foreign-trade verdict:
- Domestic communication / personal use → Sina Mail works
- Foreign trade → Must use Gmail / Outlook or a custom-domain enterprise mailbox
- Bulk cold outreach → use premium channels (don't tie to Sina)
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