Virtual SMTP servers from Mailosaur
Our SMTP servers capture every email your product sends, so you can test sign‑ups, delivery updates, and more.
What is a virtual SMTP server?
A virtual SMTP server acts like a real email server, but instead of delivering emails to the outside world, it captures them safely for testing.
With Mailosaur, every email sent via SMTP is intercepted, stored, and available for inspection, regardless of the recipient address, so nothing ever escapes into a real inbox by mistake.
How to test using Mailosaur’s SMTP server
Copy & paste your SMTP credentials
Find these in the server settings screen, and paste them into your product's settings.
Send your first email
Any email you send via SMTP will be captured by Mailosaur, regardless of email addresses used.
Inspect and test
Emails instantly appear in Mailosaur, ready to preview, validate, or automate against.
Never email a real customer by accident
Mailosaur's catch-all SMTP servers safely capture all outgoing emails, even when addresses look real.
This means you can test production-like flows safely, confidently validate edge cases, and ultimately avoid embarrassing mistakes.
Works with any email‑sending setup
Mailosaur works with any SMTP‑based system: custom code, frameworks, or third‑party email-sending providers, and fits right into your existing stack.
If your product can send email, Mailosaur can capture it.
Why teams choose Mailosaur's dummy SMTP servers
Mailosaur doesn’t just capture emails, it connects them to testing, previews, and validation in one place.
QA, product, and marketing teams can view, review, and validate messages from the dashboard without any code.
With environment‑specific servers, unlimited test addresses, and safe isolation from real inboxes, teams can test confidently.
Mailosaur is a managed platform; There’s no SMTP server to maintain, no inbox behaviour to keep up to date, and no custom tooling to secure.
Separate inboxes, specific permissions
Steer your own ship and organise your tests as you see fit. Create separate inboxes per team, role or project, and set hierarchal permissions for each, keeping your testing safe and compliant.
See, test, and validate every message
Mailosaur does far more than just capturing your emails. You can preview your emails (across devices and inboxes), inspect them for content issues, and even start running automated tests for full end-to-end flows.
Ready to give it a go?
It couldn't be easier to try Mailosaur
Book a demo with our friendly team, or start your 14-day free trial to see if Mailosaur is the right fit for you