trouble with smtp.mail.me.com

Hello 401-FPC_csp,

Welcome to Apple Support Communities. 

We understand that you’re being prompted to enter your password for your iCloud email, but the password is incorrect. We are happy to help.

What is the exact error message when you enter your password? What is the exact error message when you try to change the password? These answers can help us further isolate the cause.

If you have not done so, we recommend restarting your computer to see if you can access your iCloud account.

These steps may help: iCloud Mail server settings for other email client apps - Apple Support

"iCloud Mail server settings

• iCloud Mail uses the IMAP and SMTP standards supported by most modern email client apps. iCloud Mail does not support POP.
• If you set up an account using iCloud System Preferences or macOS Mail in 10.7.4 or later, you won't see these settings because they're automatically configured.
• Refer to your email client app's documentation for information about how to use these settings.

IMAP information for the incoming iCloud Mail server

• Server name: imap.mail.me.com
• SSL Required: Yes
• If you see an error message when using SSL, try using TLS instead.
• Port: 993
• Username: This is usually the name of your iCloud Mail email address (for example, johnappleseed, not johnappleseed@icloud.com). If your email client app can't connect to iCloud Mail using just the name of your email address, try using the full address.
• Password: Generate an app-specific password.

SMTP information for the outgoing iCloud Mail server

• Server name: smtp.mail.me.com
• SSL Required: Yes
• If you see an error message when using SSL, try using TLS or STARTTLS instead.
• Port: 587
• SMTP Authentication Required: Yes
• Username: Your full iCloud Mail email address (for example, johnappleseed@icloud.com, not johnappleseed)
• Password: Use the app-specific password that you generated when you set up the incoming mail server."

Let us know if you have further questions.

Take care.