# Rackspace Email: MX records and email verification

How Rackspace-hosted domains look in DNS, how Rackspace Email answers an SMTP verification handshake, and which verdicts to expect for addresses on it.

Updated: 2026-09-03

Rackspace Email is a hosted mailbox service for small businesses, sold directly and through many web hosts and resellers. Its infrastructure runs under the `emailsrvr.com` name, so Spaw reports these domains as `mx_provider: "rackspace"` even though rackspace.com itself, the company's corporate domain, is hosted on Microsoft 365.

## How Rackspace shows up in DNS

Rackspace Email asks customers to publish exactly two MX records, `mx1.emailsrvr.com` at priority 10 and `mx2.emailsrvr.com` at priority 20, and no others. Spaw matches the `.emailsrvr.com` suffix. Rackspace is a mailbox host: the MX target stores the mail, `mx_found` is true and `mx_implicit` is false. Hosted Exchange customers at Rackspace use different records and are classified by whatever their MX points at.

## How Rackspace answers a verification handshake

Rackspace Email typically rejects unknown recipients at `RCPT TO`, so most checks settle on the first attempt. The admin control panel lets a domain owner configure a catch-all mailbox, and domains with one answer as catch-all. Rackspace's inbound servers also apply rate limits and reputation checks, and a probe from a source they have not seen is occasionally deferred.

## What that means for your verdicts

Expect `deliverable` with `mailbox_exists: true` or `undeliverable` with `reason: mailbox_not_found` and `smtp_reason: no_mailbox` for most domains, and `risky` with `reason: catch_all` for the ones with a catch-all mailbox. For catch-all domains Spaw returns `mailbox_confidence`; Rackspace is not on the established-provider list, so the estimate depends on the domain's DMARC and SPF, its age, the username's shape and your own delivery data. There are no consumer username rules for Rackspace domains, since every Rackspace domain is a customer's own domain.

Rackspace's customers are small businesses, and their address lists carry many role inboxes: `info@`, `office@`, `sales@`. Spaw flags them `risky` with `reason: role` even when the handshake confirms they exist. Staff turnover shows up as `mailbox_not_found` once the account is deleted, and the address then joins your suppression list.

## SPF and DMARC at Rackspace

Rackspace's documentation asks domain owners to publish `v=spf1 include:emailsrvr.com ~all` when Rackspace Email is the only sender, and to enable DKIM from the control panel; any other service sending as the domain needs its own include. Spaw reports the live state in `has_spf` and `dmarc_policy`, and a company domain without SPF adds ten risk points to its addresses.

## Practical notes for sending to Rackspace users

Because most Rackspace domains belong to small companies that manage DNS through a web host or reseller, SPF and DMARC are frequently missing or misconfigured on the receiving side, which affects their own deliverability but not yours. On your side, an aligned sending domain and a clean list are enough; Rackspace's filtering is conventional. Re-verify these lists on a schedule, since small-business staff and role inboxes change often.

For a live look at any Rackspace-hosted domain, run it through the free MX lookup and the SPF and DMARC checker.

Reference: https://spaw.co/email-providers/rackspace