How to Add Japanese ISP Email Accounts

Japanese ISP mail accounts fail to add for a small number of reasons, and almost never because of a typo. Usually IMAP isn't included in what you're paying for, or the provider expects a separate mail password rather than the one you log in to their website with, or there is an access switch to turn on first.

Find your provider below. Use only that block — these providers share nothing with each other, and settings from one will never work for another.

Two things to know before you start. Your username is your full email address for every provider on this page except docomo. And yahoo.co.jp is Yahoo! JAPAN, a different company from Yahoo — see the section below, because the difference matters.

So-net (so-net.ne.jp)

Start here: IMAP is a paid add-on

So-net's own FAQ says it plainly: to use So-net mail over IMAP you have to apply for the IMAP service first. It is a separate paid option, not part of a standard So-net account. If you have not applied for it, no IMAP setting will ever connect — the service isn't switched on for your mailbox.

POP3 works without applying for anything. If you don't want the IMAP add-on, set the account up as POP3 using the values below.

So-net's own page for the IMAP service: IMAPサービス.

Outgoing mail needs authentication switched on. So-net's own settings list: メールの設定値を知りたい.

OCN (ocn.ne.jp)

Start here: the mail password is not your OCN login password

OCN issues a mail password that belongs to the email address itself. It is the one your mail app needs, and it is not the same as the password you use to connect to the internet. Entering the connection password is one of the most common reasons an OCN account won't add.

Outgoing mail needs authentication switched on, with the same address and mail password. OCN's own settings list: OCNメールの設定値と基本仕様.

@nifty (nifty.com)

Start here: new IMAP setups are being refused

@nifty's mail FAQ currently states 「現在、IMAPのメールソフト新規利用を制限させていただいております。」 — "we are currently restricting new mail-software use of IMAP" — and points people at @nifty Webmail instead. So if you are adding a nifty.com address to a mail app for the first time, IMAP may be refused no matter what you enter. That is a decision at @nifty, not a fault in BlueMail.

Use POP3 instead. POP3 is not restricted and adds normally.

Outgoing mail needs authentication switched on. @nifty's own settings list: メールソフト設定, and the IMAP notice: IMAP機能を利用したメール送受信の設定方法.

BIGLOBE (biglobe.ne.jp)

All three servers share one name. Use your BIGLOBE password, not your connection password.

BIGLOBE requires TLS 1.2. It turned off SSL 3.0, TLS 1.0 and TLS 1.1 to its mail servers in April 2023, so an old device or OS that can only offer those will be refused. Outgoing mail needs authentication switched on. BIGLOBE's own settings list: BIGLOBEメールの仕様や利用するための設定値.

J:COM (jcom.zaq.ne.jp and jcom.home.ne.jp)

J:COM issues addresses on two domains, @jcom.zaq.ne.jp and @jcom.home.ne.jp. J:COM's setup guides give the same servers for both — the server names stay on jcom.zaq.ne.jp even when your address ends in jcom.home.ne.jp. Note the extra letters: the POP server is pops, the outgoing server is smtpa.

J:COM's own setup page: メールを送受信するための初期設定.

These values are for J:COM NET addresses only. If your address is on a plain regional zaq.ne.jp domain rather than jcom.zaq.ne.jp, ZAQ says the details depend on which cable company you subscribe to — see the section on other ISPs below.

Yahoo! JAPAN (yahoo.co.jp)

Yahoo! JAPAN is not Yahoo. They are separate companies running separate mail services that happen to share a name. Our Yahoo OAuth page is about Yahoo, which signs you in with OAuth — it does not apply to a yahoo.co.jp address. Yahoo! JAPAN's own instructions for outside mail apps use IMAP or POP3 with a password, not an OAuth sign-in. Add it with Manual Setup and the values below.

Start here: three switches at Yahoo! JAPAN

Any one of these will stop the account adding, and all three are on Yahoo! JAPAN's website rather than in BlueMail.

1. Turn on IMAP/POP/SMTP access. In Yahoo!メール in a browser, open 設定 (Settings) at the top right of the mail list, go to IMAP/POP/SMTPアクセス, and set access from services other than official Yahoo! JAPAN services to 許可する (Allow). Yahoo! JAPAN recommends leaving this off, so on many accounts it is off. Yahoo! JAPAN's own explanation: 他社メールソフト等の利用について、設定確認のお願い.
2. Change your password, then use the new one. Yahoo! JAPAN has been rolling out security changes that switch IMAP/POP/SMTP access off on accounts that didn't act, and its instructions for people who can't send or receive in an outside app start with changing the password. Their notice: Gmail、Outlookなどで送受信ができない方へ.
3. Check the overseas access restriction. If setup still fails after the first two, Yahoo! JAPAN says to set 海外からのアクセス制限 to 無効 (disabled). It is listed in the same notice as step 2.

There is also a registration requirement: Yahoo! JAPAN says POP/SMTP/IMAP access requires signing up for Yahoo!ダイレクトオファー, with exceptions for Y!mobile addresses, Security Pack subscribers and additional mail addresses. Their page: Yahoo!メールのPOP/SMTP/IMAPアクセス、またはメール転送を利用したい.

Your username is your Yahoo! JAPAN ID email address and your password is your Yahoo! JAPAN ID password. Yahoo! JAPAN's setup instructions don't send you off to create an app-specific password first. Their own manual setup page: Outlook 2021の設定方法（IMAP・手動設定）.

docomo (docomo.ne.jp)

Start here: your normal password and address are both wrong here

docomo mail is the one provider on this page where the obvious credentials are not the ones to type. The username is your dアカウント ID, not your email address. And if you have issued an IMAP専用パスワード (IMAP-only password), docomo requires that one instead of your dアカウント password.

Before any mail app can connect, docomo's instructions have you:

1. Create a dアカウント if you don't have one.
2. Turn on dアカウント利用設定 in My docomo. docomo's instructions have you do this step over the docomo mobile network rather than Wi-Fi.
3. Issue an IMAP専用パスワード. In My docomo, go to 設定 | メール設定 | 設定を確認・変更する and use the IMAP-only ID and password option; you'll need your network security code (ネットワーク暗証番号).

docomo's own page for other mail apps: その他のメールアプリからのご利用, and IMAP専用パスワードの発行.

Every other Japanese ISP

For dion.ne.jp, auone-net.jp, itscom.net, commufa.jp, kcn.jp, tiki.ne.jp, regional zaq.ne.jp and home.ne.jp addresses, and the many other Japanese ISP and cable domains, there is no single correct answer to print here. Japanese ISP mail settings vary by provider, by region and by contract — the cable operators in particular run different mail servers per area, and ZAQ's own support site makes you pick your cable company before it will show you any values. A table here would be wrong for most readers.

Get your incoming and outgoing server details from your ISP's own support page or your member portal, where they are listed for your specific contract. If you are reading values off a membership certificate that arrived in the post when you signed up, check them against the provider's current support page first — printed values go out of date when a provider changes servers or ports.

You need five things: the incoming server name, its port, the incoming security type, the outgoing (SMTP) server name and its port. While you're there, check whether your provider issues a separate mail password — several on this page do.

Where these go in BlueMail

Try the normal sign-in first. On the password screen, Allow BlueMail to auto-detect the server details of your account is ticked by default — leave it ticked and tap Next. If that works, you're done.

If BlueMail can't find the details, enter them by hand:

1. First account? Tap Continue, type your email address, tap Sign in, then tap Having trouble? Manual Setup under the Sign in button. Already have an account in BlueMail? Go to Settings | Accounts | Add Account.
2. On the Choose provider screen, tap Manual Setup at the bottom.
3. Choose IMAP or POP3, to match the row you're using from the table above.
4. Fill in the form — it holds the server, Security and Port fields. Pick SSL, TLS or STARTTLS in the Security dropdown to match the table, and use your full email address as the username (your dアカウント ID for docomo).

Full walkthrough: Configuring your account manually.

It worked before and stopped

Check your provider's access switch first if it has one — Yahoo! JAPAN's IMAP/POP/SMTPアクセス in particular gets switched back to 許可しない as part of their security rollout, which stops a working account with no warning.

Otherwise check the server details saved on the account: Settings | Accounts | [tap the account] | Incoming/Outgoing Settings — see Edit Account.

Still stuck? Can't Add My Account works through the other usual causes, and Connection issues, sync failures or missing emails covers accounts that added fine but won't stay connected.