ZeroSMTP

FAQ

Answers to the questions we get asked most often about using ZeroSMTP.

Can I use ZeroSMTP with my own hosting and my own domain?

Yes. ZeroSMTP is an SMTP relay — it doesn’t care which domain your hosting or website runs on. Setup is three steps:

  1. Register a free account at msgwing.com and get a randomly generated address on the @msgwing.com domain.
  2. Configure that account’s SMTP credentials in your app, script, website, or hosting panel (server: mx.msgwing.com, port 587 with STARTTLS or 465 with SSL/TLS).
  3. Send — your application delivers mail through the relay immediately, regardless of your hosting’s own domain.

This covers contact forms, password resets, and notifications from any hosting provider, plus the other use cases in the main README (apps, scripts, printers, IoT, etc.).

Will emails be sent from my own domain (e.g. you@yourdomain.com)?

No — by design. Every message is sent from an @msgwing.com address, never from your own domain. ZeroSMTP only relays mail through the msgwing.com domain and does not send on behalf of arbitrary sender domains, mainly for anti-spam and deliverability reasons.

Your need Does ZeroSMTP fit?
Reliable outgoing mail for your app/site (contact forms, password resets, notifications) ✅ Yes, regardless of your hosting’s domain
“From” address must show your domain ❌ No — that requires your own dedicated mail server

Can I get a custom username instead of the randomly generated one?

Yes. Registration generates a random @msgwing.com address by default, but you can request a specific one (e.g. you@msgwing.com):

  1. Register an account at msgwing.com.
  2. Email your request to abuse@msgwing.com with the username you’d like and the address of the account you just registered.
  3. Once confirmed, the custom username is set permanently on your account.

What are the sending limits?

See Sending limits (rate limiting) in the troubleshooting guide.

Can ZeroSMTP receive email too?

No. See This project cannot receive email — ZeroSMTP is outgoing-only.

Why is ZeroSMTP free? What’s the catch?

There isn’t a hidden one — the trade-offs are the ones already documented on this page: mail always goes out from a shared @msgwing.com address, not your own domain (see above), and sending is rate-limited per account to keep the shared domain’s reputation good for everyone (see Sending limits).

Beyond that, per the README: your data isn’t processed for marketing or resold, and abuse accounts are actively removed to protect deliverability for everyone else. If your use case needs more than what’s documented here, ask at abuse@msgwing.com rather than assuming it isn’t supported.

Still have questions?

Contact abuse@msgwing.com, or open an issue on this repository.