Cannot get yahoo mail on Imac

Older versions of Mail on Macs is the problem...

Mac's Mail App is not as modern as iOS's Mail app, Many eMail providers now require a separate App Password different from your eMail password…

Then you may need Ways to securely access AOL Mail…

https://help.aol.com/articles/allow-apps-that-use-less-secure-sign-in

Or it may just need an App Password...

https://support.google.com/mail/answer/185833?hl=en-GB

Yahoo has gone to this too...

https://help.yahoo.com/kb/access-yahoo-mail-third-party-apps-sln15241.html

Yahoo App password…

Generate and manage third-party app passwords

Some older, third-party email apps (that do not use our Yahoo branded sign in page) require you to enter a single password for login credentials. To access your Yahoo Mail account on these apps, you'll need to generate and use an app password. An app password is a long, randomly generated code that gives a non-Yahoo app permission to access your Yahoo account. You’ll only need to provide this code once to sign in to your third-party email app.

https://help.yahoo.com/kb/access-yahoo-mail-third-party-apps-sln15241.html

Solved. In Mac Mail - Go to Add Account and Select "Other". When prompted for email / password - enter your yahoo email address. For password - go to Yahoo Security Page (https://login.yahoo.com/myaccount/security/) and Generate App Key. (Generate and manage app passwords) Use this 16 character code as password.

After three days of working with AppleCare advisors, deleting and re-establishing my ATT/Yahoo mail account (pacbell.net), including wiping all data from my iPhone and restoring from an iCloud backup, it occurred to me that it was a password problem (I had recently changed my password due to the ATT data breach). The principle of Occam’s Razor — the simplest solution, the most obvious, is the correct one: I changed my password again, then re-entered it on my iPhone, iPad, and Mac; that of course worked — no more errors — which took about 5 minutes.

Thank you randomuser and Jbokie. I'm on Monterey and this is what I did: I added a new email account and selected "other", typed in the yahoo email account name and the password that was generated from the Yahoo Security page. I typed in the password (you can copy/paste it too) but make sure there are NO spaces in the password. It will think about for a bit and then I got an error message "unable to verify account". At that point I added the username (same email account name), changed the email type to POP and changed the incoming server to pop.mail.yahoo.com and outgoing server to smtp.mail.yahoo.com. It took me a while to figure all of this out, but I was on hold with Yahoo tech support for 3 hours, so I had time. I hope this helps some else!

After a while, even after changing my Yahoo/ATT mail password (which had seemed to solve the problem), the problem emerged again — so I assumed it was an underlying authentication issue, with the Yahoo server and Mail simply not playing well together. So ultimately, I opted to use my Yahoo/ATT Security Key as the password — I had set-up the Security Key quite a while ago [https://help.yahoo.com/kb/account/manage-yahoo-account-key-sln25781.html] [https://help.yahoo.com/kb/SLN25781.html] — first deleting the YAHOO account in my Mail application and setting it up again simply as another MAIL account, under Other Mail Account (you cannot use an ordinary Yahoo password for Other Mail Account — the server will not authenticate it. Now, in doing that, actually all the folders I have on the Yahoo/ATT server populated immediately in the new Mail account, though they took a while to fully download all the saved mail. So far, though the problem blips from time to time (with the dreaded exclamation point (!) — connection problem — it self corrects rather quickly, either by quitting the Mail app and re-opening it, or sometimes by restarting my Mac, and receiving mail is now much more consistent.

By the way, using the Security Code only works on Mac OS, not iOS — that is, you cannot set-up an Other Mail Account on iOS; so while I am stuck using another password on my iPhone and iPad, I only have to suffer a latent connection from time to time.

randomuser1001 advises what should be the solution, and I thank him/her/them — I have done the same, over and over and over. That is the problem: apparently the interaction between the MacOS and iOS (or the Mail app) is iffy, often problematic. Even using randomuser's suggestion, which does work (except when it doesn't) I find that the connection to the Yahoo server is inconsistent, and I get the dreaded "!" warning — no connection. During the past two days I have been on the phone with a senior Applecare adviser, alternately deleting and rebuilding my Mail accounts, trying to find a permanent solution — she escalated the issue to the Apple engineers, who presumably will do some surgery on the OS and iOS. At one point I had set up the account on my MacStudio using "Other," on my MacBook, using the "Yahoo" set-up, and likewise two different set-ups on my iPhone and my iPad — and they were working equally well. Then the iPad failed; then the MacBook failed; then the MacStudio failed. So I went back to using only the Yahoo set-up on all four devices, having also changed my ATT/Yahoo password (not the security key) for good measure, beforehand, in the mix of possible solutions, and all four devices are now working in concert...for now. What can I say, except that I know my way well around OS and iOS; I know how to employ all these supposed fixes — now I'll wait for updates that might finally ease the relationship between Yahoo and Apple Mail.

This worked. Thanks for the tip. I think the key is to use the one time generated app password rather than the Yahoo mail password. As context I was converted to Yahoo mail by my ISP and I was able to add my mail account as yahoo on my iPhone and use my Yahoo mail password but it simply would not work on MacOS on my iMac either as yahoo or as other. Adding the account as other and using the app generated password along with typing in the imap and smtp server names for yahoo did the trick.

Boot into Safe Mode according to How to use safe mode on your Mac and dtry adding the Yahoo account from there. Then reboot normally.

Note:  if you have a wireless keyboard with rechargeable batteries connect it with its charging cable before booting into Safe Mode.  This makes it act as a wired keyboard as will assure a successful boot into Safe Mode.

My email account was recently ported from Cox to Yahoo. I created a Yahoo account using my cox.net address and password. This appeared to be accepted for the account creation in my MacBook Apple Mail. However, the account would not come Online. After numerous attempts trying different suggestions, I successfully created an "Other" mail account in Apple Mail on my MacBook. Initially, I entered my email address from cox.net and my password that works to sign in to Yahoo mail on the website. Of note, I have had no problems getting my emails on my iPhone mail and the Yahoo website, only on my MacBook. Anyway, this first attempt at creating the "Other" account failed but now I could edit the incoming and outgoing addresses. I entered the IMAP address of IMAP.mail.yahoo.com and the SMTP.mail.yahoo.com address. Along with this, I generated an App password in the Security section of the web Yahoo Mail and used this password in my new attempt to create the "Other" account. After a short delay, this was accepted and my mail started downloading from Yahoo to my Apple Mail.

Any chance Cox is your ISP?

Cox for Apple Mail…

https://forums.cox.com/discussions/internet/using-yahoo-email-in-mac-os-mail-app/151730

This worked for me, with a modified solution that also worked - I prefer IMAP to POP so that read/deleted/etc syncs across my devices, so I changed the email type to IMAP and used the following server settings:

Incoming server- imap.mail.yahoo.com

Outgoing server- smtp.mail.yahoo.com

I think that a good possibility, since they now require an App password on the computer using, but you say you tried that?

If all else fails, use a Browser to login to yahoo.com using his credentials.

I was having the same issue. I logged into Yahoo and generated an app password. I then used the POP settings to pull my mail on my iMac. The problem was it wasn’t syncing to my other devices! I tried everything I could find, but ended up having to use Outlook mail on my iMac instead of Apple mail. It was the only way to sync between my devices….

I have to say that, having dealt with this over and over and over for the past few weeks, it's a mystery. I have alternately set-up my devices (MacOS/Sonoma on a Mac Studio and and a MacBook Pro, and iOS on an iPhone and iPad) using both the Yahoo route (using my Yahoo/AT&T password) and the Other/Mail Account route (using my Yahoo Security Key), and from time to time I still get connection errors — regardless of which route I take — or if I do maintain a connection, the retrieval of email is very sluggish. In my last effort a few days ago, the Apple Senior Advisor escalated the issue to the engineers — I was informed that a software fix, from the Apple end, should be in the works. In the meantime, following another round of failed connections, I rebuilt all four devices using the Yahoo route. After that, the next day, this morning, both my MacBook Pro and iPad failed the connection test. I didn't rush to "delete and rebuild" — instead I waited it out, shutting down Mail, shutting down my MBP, shutting down my iPad…waiting; and eventually — as I said — a mystery, the connections re-established, however, still rather slow on the draw. I suspect that the Yahoo servers may be at fault; but I'm going to let the Apple engineers deal with the Yahoo people, because if I call AT&T support, I will just be told to delete the account and rebuild it. Not again. So now all my devices are working, using the Yahoo route, the AT&T/Yahoo password, and I'll let that ride.