Test multiple users. Keep every message in one private inbox.
Give your demo accounts distinct email addresses without creating separate mailboxes. Receive real emails, inspect attachments, and follow each test scenario with a clear reference. Incoming SMS is available as an optional add-on with a dedicated number in Belgium or the United States, activated the moment you ask for it.
Try Email for 7 days. Then €19/month, excluding applicable tax. Cancel before your trial ends to avoid the subscription charge.
- E-mail16/09, 15:08
hello@sample-demo.test
to demo+sample@in.demopost.net
- SMS16/09, 14:44
+32 4•• ••• •55
to +32 4•• ••• •62
- SMS16/09, 12:18
+32 4•• ••• •55
to +32 4•• ••• •62
- E-mail16/09, 11:18
info@sample-client.test
to demo+checkout@in.demopost.net
Your demo order has arrived
- From
- hello@sample-demo.test
- To
- demo+sample@in.demopost.net
- Received
- Wednesday 16 September, 15:08 (Europe/Brussels)
Hi Sample Customer, your demo order #SAMPLE-001 is confirmed.
The receipt is attached as a PDF. Names, numbers and signatures are placeholders.
1 attachment
Your application has five test users. Why are you still checking three inboxes?
These are the everyday frictions of testing and demoing message flows — and what DemoPost actually does about them.
Different test accounts need different receiving addresses.
One receiving prefix plus your own references gives every test user a distinct address, without creating mailboxes.
Test messages get buried between everyday email.
Messages sent to your DemoPost addresses land in a separate private workspace instead of your work inbox.
During a demo you switch between app, mailbox and phone.
The received message opens in the same browser window as the demo, so the story keeps running.
A “sent” status does not show what actually arrived.
You read the delivered subject, body, links and attachment instead of trusting a status flag.
Similar test messages are hard to match to a scenario.
Search and the reference in the recipient address tell you which test each message belongs to.
Show the whole journey. Including the messages.
Three test customers. No extra mailboxes.
yourapp+signup@in.demopost.net
Welcome email
yourapp+invoice@in.demopost.net
Invoice with PDF
yourapp+reminder@in.demopost.net
Payment reminder
Replace “yourapp” with your own DemoPost prefix. All references arrive in your private workspace.
Welcome to Northwind Studio — confirm your account
- From
- no-reply@northwind-sample.test
- To
- yourapp+signup@in.demopost.net
- Received
- Today, 09:12 (Europe/Brussels)
Hi Robin Sample, thanks for creating an account.
Confirm your email address to activate the workspace. The confirmation link opens in the application you are testing.
If you did not request this, you can ignore the message.
This is a self-contained illustration with synthetic data. It sends nothing, receives nothing and is not connected to any customer workspace.
How it works
DemoPost receives messages that are addressed to your DemoPost address or number. It does not intercept all outbound traffic and it does not replace your sending provider.
- 1
Create your account and start the trial
Sign up, verify your email, choose your receiving prefix and complete secure Paddle Checkout. A payment method is required before the 7-day trial starts.
- 2
Use your DemoPost address in test records
Set the email address of your test users to yourprefix+reference@in.demopost.net. Nothing changes in how your application sends.
- 3
Trigger your existing messaging flow
Run the signup, order, invoice or reminder you want to check. Your own sending provider keeps sending and may charge its normal fees.
- 4
Inspect what arrived
Open the message in DemoPost, read the real content, follow the links and preview or download the attachment.
Your existing sending provider stays responsible for sending and may charge its normal fees. Receiving a message in DemoPost confirms what your application produced — it does not prove inbox placement at Gmail or Outlook, and it does not stop messages addressed to real customers from reaching them.
What you get
One prefix, many scenario references
Use +signup, +invoice or +case123 to keep test users apart inside one workspace. References organise messages; they are not separately secured mailboxes.
Search and filter on the reference
Find a message by sender, recipient, subject or content, so you can point at the right one during a review.
The actual received email
Subject, sender, recipient and body exactly as delivered to DemoPost — not a rendering of your template source.
PDF and image attachments
Preview in the browser and download, within the supported limits of your plan (max 10 MB per attachment).
Live updates and manual refresh
New messages appear as they arrive, and a refresh button is there for when you want certainty in front of an audience.
Private workspace
Messages stay in your own workspace behind authentication. Team invitations are not part of the current plan.
Automatic cleanup
Delete a message whenever you want; everything else is removed automatically after 30 days.
Optional incoming SMS
A dedicated receiving number in Belgium or the United States, activated automatically as a paid add-on.
HTML and plain text side by side
Compare both versions of a message and spot a missing plain-text alternative before your users do.
Preview at different widths
Check how the email lays out at desktop and mobile widths — a helpful view, not an emulation of specific mail clients.
Developer kit
Plan test addresses, then copy a ready-made prompt or DEMOPOST.md file so your AI assistant always tests with DemoPost.
Explore the featureEmail Inspector
Inspect email headers, HTML and plain-text source, and reported authentication results—all alongside the message you received.
Explore the featureWhere teams use it
Software demos
Show the confirmation email and its PDF live in the demo instead of on a slide.
Read the demo playbookManual application testing
Check the receiving side of signup, invoice and reminder flows before a release.
Email testing for applicationsMultiple test users
Give five test accounts five distinct addresses without asking IT for mailboxes.
See the address guideBuilt-in Email Inspector
See the message. Understand the details.
Check more than whether your test email arrived. Explore its headers, inspect reported SPF, DKIM and DMARC results, compare HTML and plain text, and spot details worth checking before your next demo.
- Inspect authentication
Understand the receiving mail system's reported results.
- Explore the original
Inspect headers, message source and available original email files.
- Find your next check
Use plain-English explanations to investigate technical observations.
Example inspection
Northstar Studio · sign-in email
Reported by the receiving mail system from evidence available with this message.
The receiving system reported that the sending server was permitted for the envelope domain.
The receiving system reported a validated signature for the signing domain.
The receiving system reported alignment with the visible From domain.
Informational observation
Reply-To uses a different domain.
This can be intentional when replies are handled by another service. This observation is informational, not a security failure.
Suggested next check: Confirm that the Reply-To address belongs to your intended support or reply-handling system.
Developers
Built for developers and AI-assisted builders
Plan your test addresses once and let your AI coding assistant use them automatically.
Plan test addresses in seconds
Pick suggested roles (admin, billing, signup, password reset, test customers) or add your own, such as yourprefix+customer-janssens@in.demopost.net. Every address works right away, with no setup.
One address per scenario
Give each test customer, case or role its own address, so every flow stays separate and easy to check.
Instructions for your AI assistant
Copy a ready-made prompt for Lovable, Cursor, Claude or any other AI coding assistant, so it always uses your DemoPost test addresses instead of real ones.
A DEMOPOST.md file for your project
Download it or copy it, or let your AI create it with one prompt. Your test addresses and rules then live in your codebase.
Attachments included
Invoices, PDFs and other attachments sent to your test addresses can be read in your private DemoPost inbox.
How it works
- 1Open Developers in your DemoPost inbox.
- 2Choose or add the test addresses you need.
- 3Copy the prompt or the DEMOPOST.md file into your project.
Good to know
- You can use as many addresses as you like. Messages and storage count towards your plan limits.
- DemoPost only receives email: it doesn't send or reply.
- Available on every plan, including the 7-day free trial.
Pricing
Choose Email on its own, or Email + SMS with a dedicated number activated automatically. See the full pricing page.
DemoPost Email
€19/ month, excluding applicable VAT
For testing and demonstrating your application's emails.
Also available: a dedicated inbound SMS number for Belgium or the United States (+€20/month).
- 7-day free trial
- Payment method required before the trial starts
- 2,000 received emails per billing period
- 500 MB attachment storage
- 2 GB attachment downloads per billing period
- Maximum 10 MB per attachment
- 30-day message and attachment retention
- One private workspace
- Unique receiving prefix
- Plus-reference aliases
- Built-in Email Inspector
- No SMS included
- No automatic overage charges
Trial limits
- 100 received emails during the complete trial
- 50 MB attachment storage
- Maximum 10 MB per attachment
- No SMS access
Try Email for 7 days. Then €19/month, excluding applicable tax. A payment method is required before the trial starts. Cancel before your trial ends to avoid the subscription charge. SMS is not included in the trial.
Create your account, verify your email, choose your receiving address and complete secure Paddle Checkout.
DemoPost Email + SMS
€39/ month total, excluding applicable VAT
Bring incoming emails and SMS together in one private demo inbox.
- Includes all DemoPost Email features
- 2,000 received emails per billing period
- 500 MB storage and 2 GB downloads per billing period
- Maximum 10 MB per attachment and 30-day retention
- Private workspace, plus-reference aliases and Email Inspector
- One dedicated receiving number
- 250 incoming SMS segments per billing period
- Belgium: mobile number (+32) · United States: local number (+1)
- Long messages may count as multiple segments
- Incoming SMS only — no outbound messaging
- One subscription, one invoice
- Activated automatically, straight away
- Full refund if no number can be delivered
- Not included in the free trial
The €39 total includes the €19 Email subscription; SMS adds €20/month. SMS is incoming only and is not included in the trial, but you can add it during the trial by paying the first month upfront. Your number is activated automatically — if no number can be delivered, your payment is refunded in full.
All prices exclude applicable VAT. Paddle calculates the applicable tax during checkout. DemoPost receives incoming messages only; you keep your existing sending provider, which remains responsible for sending and may charge its normal fees.
Privacy and access, in plain language
DemoPost is meant for real messages carrying test data — not for production customer data. Use synthetic names, amounts and documents in your test records.
Read the Privacy Policy and Terms of Service.
- Messages belong to your own private workspace and sit behind authentication.
- Attachments can only be previewed or downloaded by someone with authorised access to that workspace.
- Messages and attachments are removed automatically after 30 days on the current plans.
- Plus references organise messages inside one workspace; they are not separately secured mailboxes.
Frequently asked questions
DemoPost is a private inbox for manual application testing and software demos. It receives real messages carrying your test data, so you can read exactly what your application produced.
Contact us
Questions about DemoPost, SMS activation or invoicing? Send us a message and we will get back to you.