Can't send/receive Yahoo! Mail in eM Client [July 2026]? → Yes, you can!

🚩 If you've tried everything and ended up here, skip to the 【 Final Resort 】.

Environment: Windows 11 PC / eM Client (Paid version) / Norton 360

I am using eM Client (Paid version, ver. 10.4.5606 (58d51c0)).
That said, I had always used the web version of Yahoo! Mail. The reason was simple: I wasn't using my Yahoo address. However, I recently changed that setup significantly. (Because my ISP, 'Plala', is shutting down next year!!)

So, the other day, I finally bit the bullet and managed to get 'Yahoo! Mail' sending and receiving in 'eM Client'.

I hope this article serves as a reference for those who, like me, were stuck looking for information on the niche combination of 'eM Client' and 'Yahoo! Mail'.

※ Just a disclaimer:
Unfortunately, this doesn't mean the tedious setup process will be any easier. This is just a record of my impressions and settings after trying information found online as someone who isn't an expert.

'Yahoo! Mail Help' - Strengthening Yahoo Security -

It seems Yahoo! Mail has strengthened its security this year to prevent unauthorized logins, placing restrictions on access from third-party email software. Accordingly, the official 'Yahoo! Mail Help' has a dedicated page for troubleshooting issues where you 'cannot send or receive mail with email software'. Furthermore, it advises contacting them with the necessary information if the issue persists. I basically followed this while setting things up. On the other hand, I couldn't find any information regarding the current Japanese Yahoo! Mail situation in the eM Client help documentation.

・ 'For customers having trouble sending/receiving Yahoo! Mail from third-party email software, etc. (IMAP/POP/SMTP)'

・ 'Cannot receive mail with email software'

【 Things I Tried 】

Since it wasn't working, in addition to the steps in the official help above, I also tried information I found online. Specifically, the following (10 items in total).

<Yahoo! side> (IMAP/SMTP)

• ① Allow 'IMAP/POP/SMTP access' (other than POP).
  ※ If using 'POP' reception, it succeeds easily with eM Client's automatic setup. (I accidentally performed the 'automatic setup' while 'IMAP/POP: Allow both' was enabled, and it unexpectedly selected 'POP' and succeeded. Immediately after, I received an email from 'Yahoo! Direct Offer' saying 'Thank you for registering', so I didn't even have to test if it worked.)
  

• ② Disable 'Access restrictions from overseas'.
  

• ③ Change the 'password' to a stronger one.
  ※ I took this opportunity to change it to 14 characters or more, mixing uppercase and lowercase letters, numbers, and symbols.
  

• ④ Set a 'Secret ID'.
  ※ Refer to A) below.
  

• ⑤ Register a 'Passkey'.
  I used the passkey for subsequent logins.
  ※ I also kept the user password login method enabled just in case until the eM Client setup was complete. See C) below for details.
  

• ⑥ Confirm 'Password: Enabled', 'One-time password: In use', and 'SMS authentication: Configured'.
  ※ Yahoo! recommends changing 'Password' to 'Disabled' after completing the eM Client setup. See C) below for details.
  

<Others (PC, eM Client side)>

• ⑦ Clear cache and restart the PC.
  

• ⑧ While setting up the account in eM Client, temporarily pause 'Norton Smart Firewall' and 'Windows Auto-Protect'.
  

• ⑨ Manually configure IMAP/SMTP server information.
  * The content is as described in the official "Yahoo! Mail Help".
  * In the intermediate step of eM Client "Test configuration", check "Ignore test results" and proceed to complete the manual entry.
  

• ⑩ While eM Client is attempting to connect to the server, open the Yahoo! site in a separate window as usual and log in to the web version using a passkey.
  * Although it ended in failure when I actually tried it, there was a display and waiting time that suggested a connection, saying "This may take some time," perhaps because it was attempting something in the background.
  

However, it still did not succeed at this point, and no matter how many times I tried, the result on eM Client was

This error kept appearing, and I kept looking back at several setting screens, wondering, "What else should I do?"

[ The final move ]

For the "Security policy" of both IMAP/SMTP,
please select "Use TLS on special port".

After trying various things, I finally changed the "Security policy" item in eM Client from "Use STARTTLS(always)" to "Use TLS on special port". Then, "✅OK" was finally displayed, and since then, I have been able to send and receive without any problems.

"So this was it..."
Once it comes to this, I don't know if all the settings and attempts I changed before were really necessary. And I didn't have the energy left to verify that.

<General settings screen>

<IMAP settings screen>

<SMTP settings screen>

Reading through Yahoo!'s procedures calmly while writing this article, it is highly likely that only ①②⑨ are essential.
Even so, if you want to gain the benefits of ③④⑤ and aim for a certain "OK",

1. Perform the above ①②③④⑤⑥(⑧)⑨.
   * ⑦⑩ are excluded because they are not listed in the official support procedures and their effectiveness is unknown.

2. For the eM Client setting "Security policy", select "Use TLS on special port" for both IMAP/SMTP.

3. If that still doesn't work, try other settings (⑦⑩). Or contact support.

I think it is better to follow this procedure.

<⑧ Image> Temporarily disabling security software

・Left-click the "∧ (notification area)" on the bottom right → Right-click Norton → Disable Smart Firewall, Disable Auto-Protect → Disable for 10 minutes

Things I quietly noticed

The basics follow the steps provided in the official support documentation, but there were about three points that made me think, "Huh?" while working on it. (From a layperson's perspective)

A) Setting a Secret ID

While failures continued, I also set a Yahoo! "Secret ID." Honestly, I don't know if it had an effect before the [Final Step] or if it was even necessary. However, I noticed that setting this Secret ID makes changing email addresses very easy on both the Yahoo and eM Client sides. Since the address does not affect authentication from eM Client to the server, for example, you can switch to any address you want to use at any time simply by rewriting the "Email" field in the eM Client settings. It might be worth setting the Secret ID in advance.


※


Regardless of the address entered in the "Email" field, emails sent to all addresses linked to your Yahoo account will arrive without any issues.

B) Trying to connect to the server with "~@yahoo.co.jp"

The domain of the address I want to use as my main one is "~@ymail.ne.jp." However, the Yahoo! brand icon was not in the list when selecting icons. So, when I tried the "~@yahoo.co.jp" domain for the new account "Email address (E):" on the first screen of "Add Account," the Yahoo! brand icon appeared as an option. After obtaining the icon, I re-entered the address I wanted to use in the "Email" field later.


※ It is not necessary for your Yahoo! "Main Email Address" to be a "~@yahoo.co.jp" domain (I have confirmed this), but if you fail, please try changing it.

C) Yahoo's support for third-party email software

The current situation with Yahoo is that they are forcing
users to switch to passkeys or SMS authentication for logging into their Yahoo "Account" or "Web version," but the way
third-party email software logs into the server is limited to the traditional password method.

Since these are two separate channels, I believe it is not necessary to set ⑥ "Password: Enabled" when configuring in eM Client.
However, some information found online always advises that it is necessary to set "Password: Enabled," and I used that as a reference.
Although the verification conditions were uncertain this time (because I was connecting from a PC that was already configured), I was able to set up (add) the account in eM Client even with Yahoo! set to "Password: Disabled."
Even considering that, the reason I included ⑥ in the recommended steps is that I recommended changing the password to a strong one in step ③, so I added it just in case. Please set it to "Password: Disabled" after the setup is complete.

Furthermore, Yahoo! Mail in the United States has an "App Password" mechanism that can be issued separately from the login password. It is a design that balances convenience and security, allowing you to individually disable only that specific password even if it is leaked.
On the other hand, Yahoo! Mail in Japan does not have this mechanism, and as a result, users are left to fumble through settings on their own as we did this time.
Gmail and others have adopted a more advanced permission system called OAuth 2.0, and eM Client already supports that OAuth 2.0. Assuming that the main third-party email software is ready, it seems to depend on whether Yahoo! Japan will support it.

If Yahoo! Japan provides a user-friendly mechanism in the future, we won't have to go through this kind of trouble. Conversely, if they move toward excluding the use of third-party email software, I will reconsider using Yahoo! Mail itself.

Summary

• Even with the (paid version of) eM Client, you will be able to send and receive Yahoo! Mail. The email environment has become comfortable, and it was worth the effort.

• Since the specifications on the Yahoo! side may change in the future, please use this article as information as of mid-July 2026 as a reference.

That is all. Thank you very much for your patience up to this point.