Quickstart

This quickstart will set up a basic email flow via p25.dev. In the second half of the quickstart you can choose to focus on Receiving or Sending emails first. Of course, you can use either of those features.

Step 1: Create an account

Accounts are tied to Passkeys and usernames. You can choose a username (not an email address) and register it together with a Passkey. Any modern browser is able to guide you through the Passkey setup process. I suggest you just try and see for yourself.

Passkeys have some advantages over other authentication flows. Depending on your local setup, they will sync across browsers. The registration flows via email (which you might not have yet), are a matter of the past.

If you should ever lose access to your Passkeys, we have a recovery process in place via email or phone support.

Before you can add a domain, you need to choose a subscription under the "Account" page. Unfortunately, some people on the internet use any opportunity to send Spam. Even if not perfect, we try to keep the potential for abuse low by putting a payment method in front of our service.

Step 3: Add your first domain

Note: Changes in configuration have a propagation time. Our p25.dev MX will not see changes immediately. Propagation should usually complete within 5 minutes. This is true for Domains, Destinations, Authentication Data and other email related configuration.

Depending on your subscription tier, you can add one or more Domains under the "Domains" page. The domain is related to your email address. If your email address is supposed to be "test@example.com", the domain you want to add is "example.com".

You can ignore the "Destination" field for now and leave it empty. You can always modify this field later. We will have a look at Destinations when configuring receiving emails down below.

Step 4: Add the verification TXT record

To make sure we only send and receive emails for a domain that you own, you need to verify domain ownership. You will need to log in to your registrar and add a TXT record. Every registrar works differently so we can't give guidance how to do this step specifically with your provider.

The record looks like this: _p25-verify.example.com TXT "p25-verification={token}"

The p25.dev page will show you if the ownership of your domain was verified or is still pending.

Make sure that you do not accidentally add a TXT record for your TLD twice (_p25-verify.example.com.example.com). This is a typical mistake people make because registrar user interfaces can be confusing.

If you happen to have dig installed, you can verify that your TXT record was properly added with dig TXT _p25-verify.example.com. You should see a response containing your token "p25-verification={token}". It can take a long time for this token to show up in public DNS, up to a couple of hours. Usually though, the record is accessible within a few minutes. Again, this depends on your registrar and some other factors.

Note: Unverified domains are automatically deleted after 48 hours. Verified domains that lose verification are kept for 45 days before deletion.

Intermediate Recap

At this point you should have an active p25.dev subscription and a configured and verified domain. Now it is your choice if you first want to try to send or receive emails via p25.dev.

Option A: Sending

For this step, you should not use an email client like Thunderbird or Apple Mail. You should use an MTA like mox or Stalwart which are able to DKIM sign emails. Signed emails are a requirement to send via p25.dev. We will not accept unsigned emails. This is for the reason that major email providers like gmail require signed emails. If we ignore this requirement, mails would be flagged as Spam or getting rejected.

Sending emails works via the following ports: 25, 587, 2587. The domain is relay.p25.dev.

You need to use STARTTLS followed by PLAIN authentication. Your custom authentication details are on the page "SMTP Auth".

We will update this documentation for detailed instructions how to configure Stalwart and mox to use p25.dev as a Smarthost in the future.

Option B: Receiving

To receive emails via p25.dev to have a backup in case your primary MX is down or in case you want to hide your MX's identity behind p25.dev, you can use a "Destination" in your configuration dashboard. You can use a descriptive text like "Stalwart" or "mox". Most people only use a single primary MX so the name is not that important but should be descriptive nonetheless.

It depends on your MX configuration on which port you are running your MX (Stalwart, mox, etc.). You can work with or without authentication. Sometimes port 25 is unavailable behind firewalls. In this case, you might want to use, for example, port 2525 and point your Destination there. Just note that p25.dev expects STARTTLS and will never send PLAIN authentication details unencrypted.

If you configured a domain, you need to add your destination to this domain, so p25.dev is able to route emails for your domain to your destination. For example, you go to "Domains" and configure your domain "example.com" to use your new destination "mox".

As a last step, you need to point your "MX" record to p25.dev so that emails correctly reach first p25.dev and then your MX. We discussed configuring DNS records in the above step for domain verification.

The recommended and only MX entry is: example.com 10 mx1.p25.dev.. While experimenting with settings, I recommend to use a TTL of 300. You can increase this value later if you like. You can have multiple MX records in place under the condition that you know what you are doing.

If you happen to have dig installed, you can verify that your MX record was properly added with dig MX example.com. You should see a response containing 10 mx1.p25.dev.. It can take a long time for this MX to show up in public DNS, up to a couple of hours. Usually though, the record is accessible within a few minutes. Again, this depends on your registrar and some other factors.

Note that changes for your Destination will slowly propagate to the p25.dev MX and should complete within 5 minutes.