---
title: "MX record conflicts"
description: "Why Mailfully's MX record sits on a sending subdomain and cannot collide with the Google Workspace or Microsoft 365 records at your apex."
---

> **For AI agents:** the complete documentation index is at [llms.txt](/docs/llms.txt). Append `.md` to any page URL for its markdown version.

Mailfully's MX record goes on `send.mail.acme.com`, not your apex. Your inbound mail MX stays at `acme.com`, and MX records are looked up per name, so the two records never compete for the same lookup.

## Why there is an MX record at all

The MX record serves the custom MAIL FROM subdomain, which is what lets SPF align and where SES routes bounce feedback. See [Publishing your DNS records](/dns/overview) for what each of the six records does.

## Where each record lives

| Name | Record | Serves |
|---|---|---|
| `acme.com` | Your mail provider's MX | Inbound mail to your organization |
| `<token>._domainkey.mail.acme.com` | Mailfully's three DKIM CNAMEs | Signing outgoing mail |
| `send.mail.acme.com` | Mailfully's MX and SPF TXT | The custom MAIL FROM subdomain |

## Google Workspace and Microsoft 365

Adding Mailfully's records does not touch inbound mail. You do not remove, replace, or modify the MX records Google Workspace or Microsoft 365 hold at your apex; Mailfully's MX lives on a different name entirely.

## One SPF record per name

The constraint people actually run into is about TXT, not MX. A single name must not carry two SPF records: publish two on the same name and both are invalid, since there's no merge step to reconcile them. Mailfully's SPF TXT lives on `send.mail.acme.com`, so it does not interact with an SPF record on your apex at all. If you already publish an SPF TXT on that exact subdomain, merge `include:amazonses.com` into the existing record instead of adding a second one.

## Verify

Query both names side by side and compare the results:

```bash
dig +short acme.com MX
dig +short send.mail.acme.com MX
```

These are separate lookups against separate names. `send.mail.acme.com` should return Mailfully's MX; `acme.com` returns whatever your mail provider publishes there, or nothing at all if the domain is used only for sending.