Same IMAP settings on every device. Username is the full address. Password is the mailbox password.
Set up Outlook
Incoming 993, outgoing 587.
Set up iPhone
Mail app, IMAP.
Set up Android
Gmail app or any IMAP client.
Open webmail
Browser inbox on mail.yourdomain.
Add DNS records
MX, mail A, SPF, Autodiscover.
Set up Thunderbird
IMAP, STARTTLS on 587.
Set up Apple Mail
Mac Mail, IMAP.
Autodiscover
The CNAME phones look up first.