Note: many clients (e.g., Thunderbird) let you configure only one incoming and one outgoing server.
Recommended (STARTTLS test, paper-default):
IMAP: host imap.13.60.158.33.nip.io, port 143, security STARTTLS
SMTP (submission): host smtp.13.60.158.33.nip.io, port 587, security STARTTLS
Optional (implicit TLS variant):
IMAPS: host imap.13.60.158.33.nip.io, port 993, security SSL/TLS
SMTPS: host smtp.13.60.158.33.nip.io, port 465, security SSL/TLS
Optional: SMTP host smtp.13.60.158.33.nip.io, port 25, security STARTTLS (some clients don't use this)
Enter this email address in your client: test-hRQ4T0kT9r@13.60.158.33.nip.io
The client should discover imap.13.60.158.33.nip.io / smtp.13.60.158.33.nip.io. If it proposes different providers/settings, switch to Manual configuration and use the settings above.