Set up MX

If you want to use p25.dev as a backup MX, you need to set a DNS MX record for your verified domain(s). The configuration depends on your preference. Do you want to hide your primary MX from the internet? Then you use a single-MX setup.

Is p25.dev your backup MX in case your primary MX fails? Then you use a dual-MX setup. Note that other email senders (especially spammers!) do not always honor the priority and some emails might still go through p25.dev even if you gave it a lower priority.

Not sure what to choose? Use a single-MX setup. It is much easier to trace and p25.dev uses settings that are battle-tested for the internet.

Option A: Single-MX

In your DNS setup, make sure you have no other MX record. If you have other MX records in place, first set the p25.dev MX record and then remove the other MX records to avoid disruptions.

• Record type: MX
• Priority: 10
• Entry: mx1.p25.dev.

Option B: Dual-MX

This is more of an expert route, and we generally do not recommend this setup.

Keep your existing MX record(s) in place and take a note about its priority setting. The p25.dev MX priority depends on your existing MX priorities. Because p25.dev has a lower priority, the p25.dev priority number has to be higher.

• Record type: MX
• Priority: usually "existing priority + 10"
• Entry: mx1.p25.dev.

Testing

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. (or another priority other than 10, especially in a dual-MX setup). It can take a long time for this MX record to show up in public DNS, up to a couple of hours. Usually though, the record is accessible within a few minutes.