Send email from your app
In shortEvery MonstarX app can send email from its own address, like pantry-notes@monstarx.app — booking confirmations, receipts, welcome notes and password resets. Ask for the email in the chat and it is built. Each app may send 50 emails an hour and 300 a day. Every email is listed under Backend → Emails. To send from your own domain, connect Resend.
Many apps need to send email: “Your table is booked for Friday at 7”, “Thanks for your order”, “Reset your password”. These are called transactional emails — one email to one person, because of something they just did. Every MonstarX app can send them, with nothing to set up and no email service to sign up for.
How do I make my app send an email?
Section titled “How do I make my app send an email?”Ask for it in the chat, and say when it should go out and what it should say:
When someone books a class, email them a confirmation with the class name, the date and time, and a link to their bookings.
MonstarX writes the email and sends it at the right moment. Password reset emails are already built in to every app with user accounts.
Which address do the emails come from?
Section titled “Which address do the emails come from?”Each app sends from its own address on MonstarX’s mail domain, monstarx.app. The name before the @ is your app’s address name, and the sender name is your app’s name, so people see something like:
Pantry Notes <pantry-notes@monstarx.app>
If you change your app’s address, the email address follows it. The app’s code can also use a different sender name for an email, like “Pantry Notes Team”. You can see the address your app sends from under BackendEmails, and in Settings, next to your app’s address — see Project settings.
How many emails can my app send?
Section titled “How many emails can my app send?”| Limit | Amount |
|---|---|
| Emails per hour, per app | 50 |
| Emails per day, per app | 300 |
| People on one email | up to 10 |
| Subject | up to 200 characters |
| Email size | up to 200 KB of text |
An email to several people counts once. The hour and the day are rolling: “this hour” means the last 60 minutes and “today” the last 24 hours. When your app reaches a limit, MonstarX refuses further emails with a message saying so, until the window moves on. Emails the mail service itself turns away are listed as Failed, with the reason.
Two kinds of email never count toward the limits:
- Test addresses. Emails to addresses that can never receive mail — anything at
example.com,example.orgorexample.net, and names ending in.test,.example,.invalidor.localhost— are not sent at all. Your app carries on as if they were, and the log shows Not delivered · test address. - QA’s test inboxes. When QA tests your app, it signs up with real test inboxes and reads the emails your app sends them, to check they arrive and their links work. These show as Sent · QA test inbox.
Where do I see the emails my app sent?
Section titled “Where do I see the emails my app sent?”Open BackendEmails. The line at the top says which address your app sends from and how many emails it has sent this hour and today, out of its limits. Below, every email is listed with who it went To, its Subject, its Status and when it was Sent.
| Status | What it means |
|---|---|
| Sent | The email left MonstarX for the person’s inbox. |
| Sent · QA test inbox | Sent to one of QA’s test inboxes during a test. |
| Not delivered · test address | The address can never receive mail, so it was skipped on purpose. |
| Failed | The email could not be sent. Hover over it, or read Failed · reason, to see why. |
Click Refresh to see new emails.
Can I send from my own domain?
Section titled “Can I send from my own domain?”Yes. Connect Resend, an email service, and your app sends from an address on your own domain, like hello@brewandbean.com, instead of MonstarX’s.
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Create a Resend account and verify your domain there.
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Open BackendCloud and, under Connectors, click Connect on Resend.
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Paste your Resend API key and the From address on your verified domain.
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Ask MonstarX in the chat: “send the app’s emails through Resend from my domain”. It rewrites the emails to go through your Resend account.
Leave Email switched on in the MonstarX Cloud list unless you are sure nothing in your app — password resets included — still sends through it.
See Connectors for how connecting works.
Can people reply to my app’s emails?
Section titled “Can people reply to my app’s emails?”Ask MonstarX to set a reply-to address, like “replies to booking emails should go to hello@brewandbean.com”. Replies then land in that inbox instead of the app’s address.
Frequently asked questions
Section titled “Frequently asked questions”Why did my test email never arrive?
If you used an address like someone@example.com, it was skipped on purpose: those addresses cannot receive mail. The log shows Not delivered · test address. Test with a real inbox of your own.
My emails land in spam. What can I do?
Ask people to add your app's address to their contacts. For the best delivery, send from your own verified domain with the Resend connector.
Can my app send newsletters to all users?
MonstarX Email is meant for one-to-one emails, with 300 a day per app. For newsletters and marketing email, use a dedicated email service and connect it.
What happens if I switch Email off?
Your app stops sending through MonstarX straight away, password reset emails included, until you connect your own provider or switch Email back on.
Does sending email cost credits?
No. Email is part of MonstarX Cloud; only the limits above apply.