Aster Mail

Overview

Aster Mail is an open-source email service from Aster Mail, a company founded in 2026 and headquartered in Orlando, Florida. It offers end-to-end encryption, custom-domain support and apps across mobile, desktop and web. Aster says its email is hosted in Germany under EU privacy law and that it does not use ads, inbox scanning or AI on the inbox.

Messages exchanged between Aster accounts are encrypted end-to-end automatically, using hybrid post-quantum encryption. This account-to-account detail is important: the stated encryption applies to mail between Aster users. Aster does not include an encrypted calendar.

The free plan is available without a trial requirement or credit card. It includes 10 GB of encrypted storage, five email aliases, one custom domain, two mail rules and access to Aster Bridge. Paid plans expand storage, aliases, domains and rules.

Key features

Encryption and privacy

Aster automatically applies end-to-end encryption to messages between its own accounts and describes that protection as hybrid post-quantum encryption. The company says its email is hosted in Germany under EU privacy law, and that there are no ads, inbox scanning or AI on the inbox. Encrypted calendar is not offered.

Desktop mail apps, migration and export

Aster Bridge supports IMAP and SMTP connections for desktop mail applications, so users can connect compatible clients rather than relying only on Aster's apps. QuickSwitch imports mail from Gmail, Outlook, Yahoo, Proton and other IMAP providers. Every plan includes one-click mailbox export at no charge, in MBOX format.

Storage, aliases and domains

Plan allowances range from 10 GB of encrypted storage and five aliases on Free to 5 TB and unlimited aliases on Supernova. Custom-domain limits range from one on Free to unlimited on Supernova. Star includes 50 GB, 15 aliases and five domains; Nova provides 500 GB, unlimited aliases and 30 domains. Free includes two mail rules, while each paid plan lists unlimited rules.

Pricing

Aster Mail uses a freemium model. The Free plan costs nothing and is described as free forever, with no credit card required. The paid prices below are listed per month when billed annually; Aster notes that the final amount is determined at checkout.

Star and Nova are listed with a 19% saving. The first paid plan has a 30-day money-back guarantee; renewals are excluded.

Platforms

Aster supports web, Windows, Mac and Linux desktop apps, and Android. Its iOS app is in beta on TestFlight. Aster Bridge offers desktop IMAP and SMTP support for connecting mail apps.

Who it's for

Aster Mail may suit people looking for an encrypted email service with a free entry plan, custom-domain support or the option to connect a desktop mail client. Its paid tiers offer larger storage and higher domain and alias limits. Users who need an encrypted calendar should note that Aster does not provide one; iOS users should also be aware that the listed app is a TestFlight beta.

Pros and cons

• Pros: End-to-end encryption is automatic between Aster accounts, with hybrid post-quantum encryption; the free plan includes encrypted storage, aliases, a custom domain and Bridge access; mailbox export is free on every plan.
• Cons: Encrypted calendar is not included; the stated automatic end-to-end encryption covers mail between Aster accounts; iOS availability is a beta on TestFlight.

Alternatives

For other services in this area, compare Proton Mail, Tuta Mail, eclipso Mail Europe, Private-Mail, Disroot Email, Mailo, mail.de and Mailfence. You can also browse our lists of Secure Email Providers, Private Email Services and Email providers.

Verdict

Aster Mail combines account-to-account end-to-end encryption with custom domains, desktop-client connections, mail migration and free MBOX export. The free plan provides a useful set of core allowances without a trial or card requirement, while paid plans raise storage and domain limits substantially. Its stated limitations are equally clear: no encrypted calendar, and automatic end-to-end encryption is described for messages exchanged between Aster accounts. Those trade-offs, together with the TestFlight status of iOS, are worth weighing against the features and allowances a prospective user needs.