Email Aliases vs Temporary Email: Key Differences
Email alias services and temporary email services like Temp90 both protect your real email address from unnecessary exposure — but they work differently and serve different use cases.
Understanding the distinction helps you choose the right tool for each situation.
What Is an Email Alias Service?
An email alias service creates a persistent alias address that forwards all received email to your real inbox. You give out the alias address to services; emails sent to the alias arrive in your real inbox (translated from the alias).
If a service sends spam or shares your address, you delete that specific alias. No emails to that alias are delivered anymore — but your other aliases continue working, and your real email was never exposed.
Popular alias services:
- SimpleLogin: Open source, free tier available, self-hostable
- AnonAddy: Open source, generous free tier
- Apple Hide My Email: Built into iPhone/Mac for App Store and web sign-ins
- Firefox Relay: Mozilla's alias service integrated with Firefox
What Is Temporary Email (Temp90)?
Temporary email provides a disposable inbox that:
- Receives email during a session
- Is not persistent — expires or can be discarded
- Does not forward to your real inbox
- Leaves no ongoing data relationship
Key Differences
Persistence
Alias: Permanent (or until you delete it). Can receive email months or years later. Temp90: Session-based. Discarded after use.
Inbox
Alias: Forwards to your real inbox. You read all forwarded email in your regular email client. Temp90: Separate inbox. You check it directly in Temp90.
Identity
Alias: Your real inbox receives the forwarded email (identity one step removed). Temp90: No connection to your real identity or inbox.
Best Use Cases
Use email aliases for:
- Ongoing services you want to continue receiving email from
- Subscription management (one alias per service — delete if it spams)
- Professional contacts where you want a consistent address
- Services where you need reliable, long-term email receipt
Use Temp90 for:
- One-time registrations you do not need ongoing access to
- Platform evaluation with no commitment
- Any registration where you do not want email forwarded to your real inbox at all
- Maximum identity separation — aliases still link to your real inbox
Combining Both Tools
An optimal privacy email strategy uses both:
Tier 3a (Temp90): Completely disposable, no forwarding. For true one-time registrations. Tier 3b (Alias service): Persistent but masked. For ongoing services where you want email but not identity exposure. Tier 2 (Secondary permanent email): For relationships requiring direct, reliable email access. Tier 1 (Protected primary): For banking, healthcare, government only.
How Alias Services Protect Privacy
When you give site A your alias (alias-a@relay.service) and site B your alias (alias-b@relay.service):
- Site A cannot match you to site B because they have different addresses
- If site A sells their list, only alias-a is exposed — not your real email
- You can instantly cut off site A by deleting alias-a — site B continues unaffected
- Data brokers cannot cross-reference between sites using your alias addresses
Frequently Asked Questions
Can email alias services see my emails?
The alias service processes your email to forward it. They see metadata (sender, subject) and potentially content depending on their architecture. Privacy-focused services like SimpleLogin aim to minimize logging, but they are not zero-knowledge by default.
Is Temp90 better or worse than an alias service?
Neither is universally better — they serve different use cases. Temp90 provides complete identity separation and requires no setup. Alias services provide persistent, managed identity protection with email forwarding. Use Temp90 for complete disposability; use aliases for managed ongoing privacy.
What if a service rejects my alias address?
Some services blocklist known alias service domains. Apple's Hide My Email uses @privaterelay.appleid.com, which may be blocklisted on some platforms. Temp90's Gmail-style addresses are less likely to be rejected.
Conclusion
Email aliases and temporary email are complementary tools addressing different privacy needs. Aliases protect your real email from ongoing services with continuous forwarding. Temp90 provides completely disposable inboxes for one-time use with no forwarding or ongoing connection. A complete email privacy strategy benefits from having both in your toolkit.