Outgoing mail server

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.

This may help you --> iCloud Mail server settings for other email client apps - Apple Support