Mail-client connection problems are often caused by using the wrong server name, port, encryption mode, username, or password.
- Open cPanel Email Accounts → Connect Devices for the mailbox and use the current secure manual settings shown there.
- Confirm the full email address is used as the username when cPanel specifies it.
- Re-enter the mailbox password rather than the cPanel account password.
- Verify the client’s IMAP/POP3 and SMTP encryption/port settings match cPanel’s displayed configuration.
- Test webmail. If webmail works but the external client does not, focus on client settings/network filtering rather than mailbox existence.
Do not disable TLS certificate verification simply to make a mail client connect.
