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Quick answer

Leave Mail closed for a moment and try a fresh sign-in at your email provider’s website. If that fails too, resolve the account problem with the provider. If it works, check the same account in Internet Accounts on the Mac. You generally do not need to reset a working password, and you should not remove an account to test a guess.

Choose the check that matches your symptom

Start with the row that describes what you see. You do not need to try every step.

Match your symptom to the relevant check
What you noticeWhere to start
Mail suddenly started asking, and you haven’t changed anythingCheck the service and avoid a password reset.
You can read old messages in a browser but Mail rejects the passwordTest whether a new sign-in actually works.
You changed the password elsewhere and webmail accepts the new oneInspect the affected account on the Mac.
Internet Accounts has no password fieldCheck which sign-in method the provider requires.
You are thinking of removing the accountProtect mail that exists only on this Mac first.

Before you start

  • Check the name of the app: these menus belong to Mail on a Mac, not Outlook for Mac, iPhone Mail, or a website.
  • Identify which mailbox shows the prompt. If you have two accounts from the same provider, note which one is affected. Never send anyone a password, recovery code or verification code.
  • Keep a working mail session open on your other device. If this is a work or school account, ask your administrator before removing it or changing its sign-in method.

Why this happens

Mail can reach the mail service and still be denied access to one mailbox. A password changed on another device, a temporary service problem, or a change to how the provider allows apps to sign in can all produce the same prompt. A browser that is already signed in is useful for checking messages, but it doesn’t tell you whether your current password will be accepted.

What to do, step by step

Try one step at a time. Stop when the issue is resolved. If an instruction doesn't match your device, use the official model-specific guidance instead.

1

Pause the prompts and check the service

  1. Dismiss the prompt.
  2. In the Mail menu, choose Quit Mail.
  3. In Safari, see whether an ordinary website opens.
  4. If it does, visit your mail provider’s known status or support page.
  5. If the provider reports a mail outage, wait for recovery and test Mail once.
If no websites open, troubleshoot the connection first. Changing the email password won’t bring the Mac online.
2

Test one fresh sign-in without closing your working inbox

  1. In a private browser window, type your usual mail provider’s web address yourself.
  2. Sign in to the same mailbox using the method you normally use.
  3. If the site rejects the password or locks the account, stop guessing and follow the provider’s own recovery steps.
  4. Leave any existing working session open.
An inbox that opens without asking is not a password test. If the provider uses a passkey or a company sign-in, a successful sign-in proves web access but does not prove an app password is valid.
3

Select the affected mailbox in Internet Accounts

  1. If webmail works, leave Mail closed.
  2. Open the Apple menu at the top left of the screen.
  3. Choose System Settings (System Preferences on older Macs), then Internet Accounts.
  4. Select the account that keeps prompting.
  5. Open Details if it is available.
  6. Only if you see a password field, replace the old password with the current one.
  7. Reopen Mail and check for a new message.
No Details button or password box? That can be normal. Go to the next step instead of editing a different account or your Mac login password.
Internet Accounts with the pointer on the example mailbox row.View larger
Original AI-generated UI example, not a captured screenshot. Select your own account name; available controls depend on the provider and macOS version.
4

If there is no password field, check the provider’s sign-in method

  1. Open the official help page for your email service or ask your workplace administrator which sign-in method it supports for Apple Mail.
  2. If the account offers a provider sign-in, follow it for that mailbox.
  3. Use an app-specific password only if the provider explicitly requires one for this setup.
  4. Then return to Mail and test again.
Do not turn off two-factor authentication or approve a sign-in you did not initiate. No one needs your code to explain which sign-in method to use.
5

Protect local messages before considering account removal

  1. Compare the important folders and messages in webmail with the same account in Mail, including drafts and sent mail.
  2. If something exists only on the Mac, keep the account.
  3. To copy messages into an existing local mailbox, select them, Control-click, choose Copy To and select a mailbox under On My Mac.
  4. Open the destination and check the copies before going further.
If the provider specifically recommends removing and re-adding the account, first make and verify a backup of anything you cannot recover from webmail. Stop and ask for help if you have no local mailbox, no verified copy, or a managed device. Removing an account can remove its downloaded messages from this Mac.
Saved Mail shown beneath On My Mac in the Mail sidebar.View larger
Original AI-generated UI example, not a captured screenshot. Saved Mail is an example name. A mailbox under On My Mac stores local copies.
6

Export and check a separate copy if mail exists only on the Mac

  1. Keep the affected account in place. Connect an existing suitable backup drive with enough free space; do not erase it.
  2. In Mail, select the mailbox you need to preserve. Choose Mailbox > Export Mailbox.
  3. Choose a private folder on the backup drive and click Choose. Wait for the export to finish; it creates an .mbox package.
  4. To check the export, choose File > Import Mailboxes in Mail. Select Apple Mail, click Continue and locate the exported mailbox.
  5. Open the new Import mailbox and check the important messages and attachments. If anything is missing or the export fails, stop and leave the account unchanged.
An export only preserves mail available to the Mac. It does not prove that every message on the server or iPad was downloaded. Keep the original messages and a separate verified copy before changing the account.

Still not working? Know when to stop

If webmail rejects the sign-in, contact the email provider; for a managed mailbox, contact your administrator. If webmail works but the Mac keeps prompting even after you use the provider’s supported sign-in method, tell support which account type, macOS version, and step failed. Mention whether webmail works in a fresh window and whether any messages exist only on the Mac. Do not send login details. Leave the account in place until your messages are safe.

Write down the exact model and error message before contacting official support.

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Useful tools, only if they fit your situation

Try the free checks first. Compare these optional products for the specific uses below; buying equipment does not guarantee a fix.

A backup drive protects an exported copy; it does not fix authentication. Follow step 6 and verify the archive before relying on it. Use a drive you already own or a smaller suitable capacity when that is enough. Do not buy storage if the problem is simply an incorrect sign-in and all mail is safely available elsewhere.
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  • For a separate archive of mail already available on a MacOptional

    Samsung T7 Shield portable SSD — 2 TB, black

    Store exported local Mail mailboxes before a provider-guided account removal. Use an existing suitable drive first. This 2 TB option makes sense when you also need room for a larger personal backup archive; a small mailbox alone does not need this capacity.

    • Exact model MU-PE2T0S/AM; 2 TB external solid-state storage.
    • USB 3.2 Gen 2 connection; check the Mac’s ports and a compatible data cable.
    • An exported copy must be checked before relying on it. One drive is not an entire backup strategy.

    Consider only when: Important messages exist only on this Mac, you need a separate export before account changes, and you do not already have suitable backup storage.

    Check compatibility: This workflow uses Mail on a Mac. Plugging the drive into an iPad does not export its Mail database or repair deletion syncing. A drive cannot restore a rejected password or download messages you cannot access. Do not erase or reformat a drive that holds data; keep mail archives private.

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Frequently asked questions

Does this mean my Mac login password is wrong?

Usually the prompt is about an email account. Use the account name in the prompt to identify it; changing the password that unlocks your Mac is not a fix for a rejected mailbox sign-in.

Why does my phone still receive mail?

The phone may already be signed in. Keep that working session. A fresh sign-in at the official provider website helps distinguish a mailbox-access problem from a problem limited to Mail on this Mac.

Will removing the account delete my email?

Mail removes the account’s messages from the Mac. Messages still on the provider’s server remain there. If a message is not visible in webmail, do not assume it is backed up. Preserve local mail before removing anything.

Should I buy a password manager or a security key?

Neither will restore access to a mailbox that rejects your sign-in. Use the provider’s supported method first. A new security key cannot stand in for a recovery method already registered with the account.

Sources and editorial transparency

Documentation checked: 2026-11-05. Our instructions are written for this guide. Interface labels can change; this is a source review, not hands-on testing of every device.

Reference titles and source dates
  • Apple — If Mail on your Mac keeps asking for your password — source dated 2026-07-15
  • Apple Mail User Guide — Add and manage email accounts in Mail on Mac
  • Apple Mail User Guide — Move or copy emails between mailboxes
  • Apple — Import or export mailboxes in Mail on Mac

Prepared by TechTweety Editorial · Source-backed troubleshooting guide.