1. What is SimpleLogin

SimpleLogin is an email-alias service: it gives you throwaway or long-term aliases that forward mail to your real inbox. You can reply from the alias without revealing your true address, turn an alias off if it starts getting spam, and even use your own domain. It’s open-source and part of the Proton family.

2. Core concepts

  • Alias — A public address you hand out. Mail to it is forwarded to your real inbox.
  • Reverse alias — Lets you reply; SimpleLogin rewrites headers so the recipient only sees the alias.
  • Catch-all — Any address at your domain/subdomain works automatically (great for per-site aliases).
  • Directory (subdomain) — e.g., [email protected]; memorable and fast to generate.
  • Status controls — Per-alias toggle: active, pause, block sender, delete.
  • PGP — Optional encryption from SimpleLogin to your destination mailbox.

3. What you need

  • A destination inbox (Proton Mail works out of the box; any IMAP mailbox is fine).
  • A second factor for sign-in (TOTP or security key recommended).
  • Optional: a domain you control (for custom aliases & catch-all).

4. First-time setup

  1. Create a SimpleLogin account and verify your destination mailbox.
  2. Enable 2FA in account settings.
  3. (Optional) Upload your PGP public key so forwarded mail is encrypted at rest in transit to you.
  4. Install a browser extension and/or mobile app for one-click alias generation.
  5. Create your first alias and send yourself a test message; then hit Reply from your inbox—confirm the recipient only sees the alias.

5. Everyday use

Use one alias per website or merchant. If an alias leaks or starts receiving spam, flip it off (or delete) without impacting your main inbox. For support threads, just reply as normal from your destination mailbox; SimpleLogin handles the rewrite so your identity stays hidden.

Point MX (or set the provided records) so SimpleLogin can receive mail for your domain. Turn on catch-all and you can improvise addresses on the spot—e.g., [email protected], [email protected]. This keeps deliverability high and makes aliases memorable.

Minimal records to expect

  • MX → SimpleLogin mail servers
  • SPF include
  • DKIM selector (TXT)
  • (Optional) DMARC policy for reporting/quarantine

7. Privacy & security model

  • What SimpleLogin sees: the alias, the sender, and routing metadata required to deliver the message. With PGP enabled, the forwarded content to you is encrypted.
  • What recipients see: the alias only, not your destination mailbox.
  • Logging: delivery logs exist for a short window for reliability/abuse handling (typical for email relays).
  • Threat model tips: use Tor/VPN for the web app if needed; prefer aliases over plus-addressing; don’t reuse aliases across unrelated services.

8. Patterns that work well

  • Per-site aliasing — [email protected]. Easy to audit and block.
  • One-shot signups — Create, verify, then pause the alias. Unpause when you need password resets.
  • Newsletter filter — Route a newsletter alias to a separate folder using rules in your destination inbox.
  • Team inbox — Point aliases at a shared mailbox; rotate or disable when staff change.
  • PGP for sensitive mail — Turn it on if your destination mailbox supports it.

9. Deliverability & reliability

Aliases deliver best when authenticated. If you use a custom domain, configure SPF, DKIM, DMARC. For replies, ensure your destination mailbox can send via SimpleLogin’s reverse-alias; don’t change the From manually—hit Reply so headers stay correct.

10. Troubleshooting

Symptom Likely cause Fix
Replies reveal my real address Manual compose instead of reply via reverse-alias Always Reply to the forwarded message; don’t start a fresh thread.
Alias can receive but not send Reverse-alias disabled or provider blocked Reply to a recent forwarded mail; check headers; contact support with message-ID.
Mail landing in spam Missing SPF/DKIM/DMARC on custom domain Add/verify DNS records; send a few clean messages to train the provider.
Alias never receives DNS not propagated or MX misconfigured Re-check domain verification page; wait, then retest.
PGP garbled in inbox Wrong public key or missing private key locally Re-upload correct key; confirm your mail client can decrypt.

11. Quick checklist

  • Turn on 2FA.
  • Create one alias per service.
  • (Optional) Add custom domain + SPF/DKIM/DMARC.
  • Test reply flow; ensure real address is hidden.
  • Use PGP if your mailbox supports it.
  • Pause or delete aliases that start getting spam.

12. Glossary

Alias — Public address you share; forwards to your real inbox.
Reverse alias — Temporary address SimpleLogin uses so your reply stays masked.
Catch-all — Accept any local-part at your domain and route it to your inbox.
SPF/DKIM/DMARC — DNS mechanisms that prove legitimacy and improve deliverability.
PGP — End-to-end encryption system using public/private keys.

13. Next steps

Migrate a handful of noisy subscriptions to per-site aliases, spin up a catch-all on your own domain, and enable PGP for sensitive flows. After a week, prune or pause any aliases you don’t need—your inbox (and future self) will thank you.