Email Providers
Email Providers in this category are standalone services that can be used independently—without requiring a domain registrar, ISP contract, or server rental. All services are hosted in Japan and operated by Japanese companies, offering reliable infrastructure for users who prioritize data residency, privacy, and local support.
Email services bundled with domain registrars are not listed here, but are covered under the appropriate Domain Registrars listings.
Highlighted Features:
- WebWebMail: access email through a web browser
- POP3POP3: legacy download-based access to email
- IMAPIMAP: synchronization-friendly access across devices
- DomainCustom Domains: use your own domain name for email addresses
Limitations
- CalDAV/CardDAV support is extremely rare; we did not identify any providers currently offering it.
- Exchange compatibility is generally unavailable from Japanese providers. This functionality is typically tied to Microsoft 365 or other foreign-hosted solutions, which fall outside the scope of AltStack.jp.
- A lightweight mail hosting plan by Sakura Internet, offering custom domain email, webmail, IMAP/POP3 access, spam filtering, and virus scanning, fully hosted in Japan.Read more →
- A long-established Japan-based free email service operated by Yahoo! JAPAN, fully hosted in domestic data centers.Read more →
