Email Settings GuideQuick answer: OCN email runs on OCN Mail. Every protocol connects to imap.ocn.ne.jp. IMAP is on 993, POP3 on 995 and SMTP on 465, each secured with SSL. Your username is the full address and the mailbox password you set in OCN Mail settings lets you in. Your exact values also sit under Certificate Trap in OCN Mail settings. Leaving OCN but want to keep the address? There is a paid plan.
What Changed Recently#
A host changes how you sign in more often than it changes the server names. Here is the current status for OCN and what it means for your setup.
Worth knowing
The certificate values can be stale. OCN moved its mail servers, so the settings printed on the old membership certificate can point a client at a host that no longer answers.
Worth knowing
The plain ports are gone. A client uses 993, 995 and 465 with SSL. Ports 587 and 25 are no longer usable on OCN.
Worth knowing
The mail password is its own. The password for the mailbox can differ from your OCN member login, so reset it in the OCN pages if a client keeps refusing it.
Before You Begin#
Handle these two basics before anything else. Skip them and your email app will reject the connection even when every server value is correct.
1. Create the mailbox
Add the address under your mail settings in OCN Mail settings and set its password. That password is the one your apps use.
Where: OCN Mail then your mail settings
2. Open the certificate trap
Click the current OCN servers next to the address, then the certificate trap to read the server name and secure ports.
Where: Certificate Trap
About OCN Mail#
OCN is the internet-provider mail of NTT Communications, one of Japan's largest providers. A mailbox carries an ocn.ne.jp address and reads over IMAP or POP in Outlook, Apple Mail or Thunderbird, as well as in the OCN webmail.
Incoming mail uses imap.ocn.ne.jp on 993 with SSL. Outgoing uses smtp.ocn.ne.jp on 465 with SSL. The part that trips people is the paper membership certificate. OCN moved its mail servers, so the values printed on the old certificate can point a client at a host that no longer answers. The current servers are the ones to enter.
| Service Name | OCN Mail, ISP webmail |
| Run By | NTT Communications, Japan |
| Address Domain | ocn.ne.jp |
| Incoming Server | imap.ocn.ne.jp 993 (POP pop.ocn.ne.jp 995) |
| Outgoing Server | smtp.ocn.ne.jp, port 465 SSL |
| Password | The OCN mail password, set for the mailbox |
| Webmail | OCN webmail |
OCN Webmail Login#
You can always read your mail in a browser. The official sign in pages are:
Do Not Trust the Membership Certificate#
OCN mailboxes came with a paper membership certificate that printed the server settings. OCN has since moved its mail servers, so those printed values can be out of date. OCN itself says to use the current table rather than the certificate.
| Use this now | Value |
|---|---|
| Incoming (IMAP) | imap.ocn.ne.jp, 993, SSL |
| Incoming (POP3) | pop.ocn.ne.jp, 995, SSL |
| Outgoing (SMTP) | smtp.ocn.ne.jp, 465, SSL |
OCN IMAP Settings#
IMAP is the incoming choice OCN points most people to. Mail stays put on the server, so a laptop and a phone read one shared inbox. Pull the exact server name from the certificate trap in OCN Mail settings.
| IMAP Server | imap.ocn.ne.jp | |
| Port | 993 | |
| Encryption | SSL/TLS (required) | |
| Username | Your full email address, including @ocn.ne.jp | |
| Password | Your mailbox password | |
| Authentication | Required |
OCN POP3 Settings#
POP3 downloads mail to 1 device. Pick it only if you want a local copy on a single computer. Not sure? See the comparison below.
| POP3 Server | pop.ocn.ne.jp | |
| Port | 995 | |
| Encryption | SSL/TLS (required) | |
| Username | Your full email address | |
| Password | Your mailbox password |
OCN SMTP Settings#
SMTP handles outgoing mail. If you can read mail but not send it, the problem is here.
| SMTP Server | smtp.ocn.ne.jp | |
| Port (SSL) | 465 | |
| Encryption | SSL or STARTTLS (required) | |
| Username | Your full email address | |
| Password | Same as incoming mail | |
| Authentication | Required. Switch on outgoing server authentication in the client. |
465 with SSL. Many home connections block port 25. Confirm outgoing authentication is on.
Check OCN IMAP Settings Online#
You don't need to download anything to check OCN IMAP settings online. This page is the lookup: every value is verified, current and copyable straight from your browser. Not sure your address uses OCN servers? Type it below and find out instantly.
Does my email address use these settings?
Runs in your browser only. Your address is never sent anywhere or stored.
Want to verify the account itself before configuring an app? Sign in at OCN webmail, which confirms your address and password work, then confirm an OCN mail password exists. If both pass, any email app connects with the tables above.
Look Up IMAP Settings for Any Email Domain#
This page covers OCN. For every other address, work email on a company domain included, we run a free online lookup database: imapsettings.com.
imapsettings.com
Complete email settings database, by Univik
Enter any email address and get the incoming and outgoing server settings for that domain in 1 step:
Your address is used only to find the settings for that domain. Nothing is stored or shared.
Username and Password#
Both come from the mailbox itself. The username is the whole email address and the password is the one you chose when you built the address in OCN Mail settings. A standard OCN mailbox uses no OCN mail password.
Username is the full address
Type you@ocn.ne.jp in full, with the part after the at sign. OCN turns down a bare mailbox name.
Put that same address on both incoming and outgoing.
Password is the mailbox one
This is the webmail password you set under your mail settings in OCN Mail settings, not your OCN client area login. Reset it there if an app keeps refusing it.
The two factor prompt in the OCN client area guards billing, not the mailbox connection.
Set Up OCN in Email Clients#
The servers and ports are always the same. Only the menus differ. Jump to your app:
Outlook (Windows and Mac)
- In Outlook select Add Account, then turn on manual setup under Advanced options.
- Choose IMAP and set incoming to
imap.ocn.ne.jpon 993 with SSL. - Set outgoing to the same server on 465 with SSL.
- Enter the full address and mailbox password when Outlook prompts you.
- Send a test message to yourself to prove both paths.
Apple Mail (macOS)
- In Mail select Add Account, then pick Other Mail Account.
- Give your name, OCN address and password, then continue.
- Enter imap.ocn.ne.jp with SSL on incoming and outgoing.
- Keep the SSL ports so nothing sends in plain text.
- Save and wait for the mailbox to load.
iPhone and iPad
- In Settings open Mail, then tap Mail Accounts and Add Account.
- Tap Other then Add Mail Account and fill your details.
- Keep IMAP chosen and put imap.ocn.ne.jp in both server boxes.
- Leave the secure ports iOS fills, since OCN expects SSL.
- Tap Save and let iOS run its check.
Android
- Open your mail app and tap Add account, then Other or IMAP.
- Put in your address and password. Switch to manual setup if it stalls.
- For incoming use imap.ocn.ne.jp on 993 over SSL.
- For outgoing use smtp.ocn.ne.jp on 465 over SSL.
- Save and swipe down to fetch your mail.
Thunderbird
- In Thunderbird pick Account Actions, then Add Mail Account.
- Type your name, OCN address and password, then Continue.
- Wait for detection, then make sure IMAP with SSL is picked.
- If detection fails, type imap.ocn.ne.jp in yourself.
- Hit Done and the folders fill in on the first sync.
OCN Webmail Settings#
Server settings connect your apps. The controls here shape how the mailbox acts on its own. They live in OCN webmail, opened in any browser.
Signature
Add one in the webmail preferences. It rides on mail sent from webmail. A desktop app keeps a signature of its own.
Vacation Auto Reply
Set an autoresponder in OCN Mail settings and give it start and end dates. The OCN server delivers it, so it fires even when your machine is off.
Filters and Folders
Create filters from the OCN webmail filters in OCN Mail settings. A server side rule sorts a message ahead of any device fetching it. A rule set inside an app only works while that app is running.
Spam and Blocked Senders
OCN runs SpamAssassin on incoming mail. Set the threshold and block unwanted senders in OCN Mail settings. Flagged mail lands in the junk folder for a look.
POP3 vs IMAP#
| Feature | IMAP | POP3 |
|---|---|---|
| Where mail lives | On the OCN server | Downloaded to 1 device |
| Multiple devices | ✅ Everything stays in sync | ❌ Each device sees different mail |
| Sent and deleted mail | ✅ Synced everywhere | ⚠️ Stays only on that device |
| Offline reading | ⚠️ Cached mail only | ✅ Full local copy |
| Server storage used | Yes, counts against your quota | Can be freed after download |
| Best for | Phone + computer, everyday use | Single PC, local archives |
OCN Mail at a Glance#
Every current value for an ocn.ne.jp address in one place. Use these rather than an old certificate:
| Incoming (IMAP) | imap.ocn.ne.jp, port 993, SSL |
| Incoming (POP3) | pop.ocn.ne.jp, port 995, SSL |
| Outgoing (SMTP) | smtp.ocn.ne.jp, port 465, SSL |
| Authentication | Required, same login as incoming |
| Username | Full ocn.ne.jp email address |
| Password | The OCN mail password |
| Webmail | OCN webmail |
Troubleshooting OCN Connections#
Find the exact error your email app shows, then apply the fix:
| Error you see | What it means | Fix |
|---|---|---|
| Username or password rejected | Short username or wrong password | Use the full email address with the mailbox password from OCN Mail, not the client area login. |
| Cannot send on port 25 | ISP blocks the default SMTP port | Switch outgoing to 465 with SSL. |
| Settings from the certificate fail | The printed values are out of date | OCN moved its servers, so the certificate can list an old host. Enter the current imap.ocn.ne.jp on 993 and smtp.ocn.ne.jp on 465, both with SSL. |
| Sending fails on port 587 | 587 and 25 are no longer usable | OCN accepts outgoing mail on 465 with SSL only. Set the outgoing port to 465, turn authentication on, then use the same login as incoming. |
| Cannot connect to server | Wrong port or encryption | Set 993 with SSL incoming and 465 with SSL outgoing. A firewall on your own machine can block it as well. |
| Repeated password prompt | Short username or a typo | Clear the saved login, then put in the full address with the mailbox password. |
| Messages stuck in Outbox | SMTP authentication is off | Enable "outgoing server requires authentication" with the same login as incoming mail. |
| Address stopped after leaving OCN | Free OCN Mail ends with the line | The free ocn.ne.jp mailbox is cancelled together with the OCN internet service. Only OCN's paid Value Plan keeps the address working after the line ends. |
| Lost all mail after cancelling | Stored mail is deleted on cancellation | Cancelling the line without the Value Plan removes the stored mail. Back up anything you need first. Join the Value Plan before the line ends if you want to keep the address. |
Reader Reported Fixes
Copy from the certificate trap. When a manual setup will not connect, the the certificate trap page in OCN Mail settings prints the exact server name and ports for that mailbox. Pasting those in clears the guesswork behind most failed setups.
Test the login in webmail first. Sign in at webimap.ocn.ne.jp with the full address and mailbox password. If webmail works, the credentials are right and the issue sits in the app settings.
Keeping Your OCN Address After You Leave#
An ocn.ne.jp address comes free with an OCN line, so it is tied to that line. Cancel the OCN internet service and the free mail ends with it. The stored mail is removed as well. If you want to keep the address, OCN has a paid plan for that.
The plan is OCN's Value Plan, a paid monthly option (275 yen a month, tax included). Joining it keeps your ocn.ne.jp address working after the internet service ends. It works even if your new connection is with another provider. You apply through OCN, best done around the time you cancel so the address does not lapse. Without it, the free OCN Mail cannot be kept on its own once the line ends.
| If you leave OCN | What happens to the address |
|---|---|
| Cancel, no plan | Address ends with the line, stored mail deleted |
| Join the Value Plan | Address stays, 275 yen a month |
| On another provider | The Value Plan still keeps OCN mail |
Moving Mail In or Out?#
OCN mail speaks plain IMAP, so a mailbox moves in or out like any OCN account. Each folder stays on the server until the move finishes.
Take a copy first. Back up the mailbox before a move. A note that arrives mid switch can sit on either side. A copy keeps you safe.
Carrying mail across? The Univik Email Migration Tool moves each folder over an IMAP link. Give it the OCN server name and mailbox password on this side and the other account opposite.
Rather hand it off? Our Email Migration Services team runs the whole move and verifies each folder arrived.
Use These Settings in Univik Email Backup#
The same IMAP settings above let you download your complete OCN mailbox to your computer. Univik Email Backup saves everything as PST, MBOX, EML or PDF files you keep forever, even if the account closes.
- Download Univik Email Backup and install it on Windows.
- Select OCN from the source list. If it isn't listed by name, choose IMAP.
- Give the complete email address with your mailbox password. The login name is always the whole email address.
- When the backup tool wants server details, hand it imap.ocn.ne.jp on port 993 with SSL for OCN. Take those values straight from the IMAP table above, with port
993over SSL. - Pick a saving format and folder, then start the backup. Large mailboxes download in the background.
Univik Tools That Use These Settings#
Many people land here while migrating or archiving a mailbox. All 3 tools use the same IMAP settings from this page:
Email Backup
Download your complete OCN mailbox to PST, MBOX, EML or PDF before switching or closing the account.
Email Backup Tool →
Email Migration Tool
Copy every folder from OCN straight into Gmail, Microsoft 365 or any other account. No manual export needed.
Email Migration Tool →
Email Converter Tool
Already have MBOX, EML or OST files from an old export? Convert them to PST, PDF or any format your new app opens.
Email Converter Tool →Prefer to hand the whole migration to experts?
If the hostnames and passwords feel like busywork, you can let the tool handle it. Univik's migration team handles the complete project: planning, transfer, verification and a report showing every folder made it. Since 2013, for single mailboxes up to full company moves.
Email Settings Glossary#
IMAP
Internet Message Access Protocol. Reads mail that stays on the OCN server, so every device shows the same inbox. Use imap.ocn.ne.jp on port 993 with SSL.
POP3
Post Office Protocol version 3. Downloads mail to one device. Use pop.ocn.ne.jp on port 995 with SSL if you prefer POP.
SMTP
Simple Mail Transfer Protocol. Sends your outgoing mail through smtp.ocn.ne.jp on port 465 with SSL. OCN keeps 465 as the one outgoing port.
SSL and TLS
The encryption OCN requires on 993, 995 and 465. The plain ports are gone, so a client has to use these secure ones.
OCN Membership Certificate
The paper 会員登録証 that came with your OCN contract. It lists server settings, but OCN warns those printed values can be out of date, so use the current table instead.
OCN Mail Password
The password for the mailbox itself, which can differ from your OCN member login. Reset it in the OCN webmail or member pages if a client keeps refusing it.
Full Email Address
Your username for the server is the whole address, like you@ocn.ne.jp. Type it in full on both the incoming and the outgoing server.
SMTP Authentication
The server-requires-authentication setting on smtp.ocn.ne.jp. Turn it on with the same login as incoming, so OCN lets your mail out.
OCN Webmail
The browser view of your mail. Handy for a quick check, plus a way to confirm your OCN mail password before you set up a client.
Current Servers
The values in use now: imap.ocn.ne.jp, pop.ocn.ne.jp and smtp.ocn.ne.jp with SSL. These replace older host names OCN once used.
Port 465
The one outgoing port on OCN. Ports 587 and 25 are no longer usable, so send over 465 with SSL.
OCN
The internet-provider mail of NTT Communications in Japan. Addresses end in ocn.ne.jp and read over IMAP or POP in any mail client.
OCN Value Plan
The paid monthly option that keeps your ocn.ne.jp address after the OCN line ends. It costs 275 yen a month and works even if you move to another provider.
Address Deletion
What happens to a free OCN mailbox when the line is cancelled without the Value Plan. The address stops working and the stored mail is removed.
Provider-Independent Mail
Mail you keep regardless of who supplies your internet. The Value Plan turns an OCN address into this, so it survives a move to another provider.
How We Verify These Settings#
Univik builds email backup, migration and converter software since 2013. Our tools sign in to OCN over IMAP and SMTP every day for thousands of users, so a changed server, port or login rule shows up in our connection logs before most guides notice it.
Every value on this page is confirmed with three checks: a live IMAP and SMTP connection from Univik Email Backup, a comparison against the OCN guides and a sign in with a real mailbox using the full address. We re verify after any provider announcement and at least once a quarter.
Found something that no longer matches what OCN shows you? Tell us and we will retest and update the page, with the change logged in what changed recently.
Help & Support
Frequently Asked Questions
Incoming is imap.ocn.ne.jp on port 993 with SSL. For POP the host is pop.ocn.ne.jp on port 995. Outgoing is smtp.ocn.ne.jp on port 465 with SSL. The username is your full ocn.ne.jp address.
OCN moved its mail servers, so the values printed on the old membership certificate can point at a host that no longer answers. Use the current servers instead: imap.ocn.ne.jp, pop.ocn.ne.jp and smtp.ocn.ne.jp, all with SSL.
Send through smtp.ocn.ne.jp on port 465 with SSL. Ports 587 and 25 are no longer usable on OCN, so 465 is the one to set. Turn authentication on with the same login as incoming.
The OCN mail password, which is set for the mailbox and can differ from your OCN member login. If a client keeps refusing it, reset the mail password in the OCN pages, then update the client.
IMAP is the better default. It keeps mail on the OCN server so a phone and a laptop show the same inbox. POP downloads to one device, which suits a single machine you back up yourself.
Your username is the full address, like you@ocn.ne.jp. Type the whole thing on both the incoming and the outgoing server. The password is the OCN mail password.
Open the OCN webmail and sign in with your OCN mail address and password. Webmail is the quickest way to check mail without a client. It also confirms your mail password before you set one up.
Start with the server names. A client set up years ago (or from the paper certificate) can be on an old host. Replace the incoming with imap.ocn.ne.jp on 993 and the outgoing with smtp.ocn.ne.jp on 465, both with SSL.
An ocn.ne.jp mailbox comes with the OCN internet service. It reads over IMAP and sends over SMTP at no extra charge. Set imap.ocn.ne.jp and smtp.ocn.ne.jp in your client, then sign in with your OCN mail password.
Yes, but only through OCN's paid Value Plan, which costs 275 yen a month and keeps the address working even on another provider. Without it, the free ocn.ne.jp mailbox is cancelled with the line and the stored mail is deleted, so apply around the time you cancel and back up your mail first.
Other Email Provider Settings
Summary: OCN Settings at a Glance
- IMAP: imap.ocn.ne.jp, port 993, SSL/TLS
- POP3: imap.ocn.ne.jp, port 995, SSL/TLS
- SMTP: smtp.ocn.ne.jp, port 465
- Username is always your full email address
- OCN mailbox on the OCN servers
- Pick IMAP for phone + computer sync
- Full address as the username
- Username is always the full email address