Do not guess these. cPanel generates the exact values for your account.
WHERE
cPanel > Email Accounts > Connect Devices beside the mailbox. The page lists hostname, ports and encryption, and offers automatic configuration for some clients.
TYPICAL VALUES
- Incoming server: mail.yourdomain.com
- IMAP: port 993 with SSL/TLS
- POP3: port 995 with SSL/TLS
- Outgoing server: mail.yourdomain.com
- SMTP: port 465 with SSL/TLS, or 587 with STARTTLS
- Username: the FULL email address
- Password: the mailbox password
- Outgoing authentication: required
WHY THE HOSTNAME MATTERS
mail.yourdomain.com only works once the domain resolves to us and AutoSSL has covered that hostname. Before then, use the server hostname from your welcome email to avoid a certificate warning.
THE SETTING PEOPLE MISS
Outgoing authentication. Without it the server refuses to relay, and the client reports a vague sending error that looks like a password problem.
