One of three services built on your Senders list
Managed SPF
Stop fighting
the 10-lookup limit.
mxio builds your SPF record from your Senders list and keeps it current — resolving every sender to IP addresses and republishing automatically as providers rotate. One DNS change on your end; after that you add senders from your dashboard, not DNS. Your record stays whole and under the 10-lookup limit.
Why SPF breaks
RFC 7208 limits SPF evaluation to 10 DNS lookups. Every include:, a, and mx mechanism counts. Add Google Workspace, SendGrid, Salesforce, Mailchimp, and a few more — you hit the limit before you realize it.
When you exceed 10 lookups, receivers return permerror — which DMARC treats as an SPF failure. Mail from legitimate senders gets flagged or rejected.
The standard fix is manual flattening: resolve the IPs yourself and hardcode them. It works until a provider changes their infrastructure — which they do, without announcing it.
Two ways to use mxio for SPF
It's not all or nothing. Let us maintain your SPF record, or keep it yourself with our guidance—either way you see every sender and stay under the lookup limit.
Managed
We maintain your SPF record
One DNS change on your end. We build your SPF record from your Senders list, keep it under the 10-lookup limit, and republish automatically as providers rotate their IPs. You still own the record and can reclaim it anytime.
Guided / self-managed
You keep the pen
Keep managing your own SPF record. mxio shows you every sender, the exact record to publish, and flags when you're near the lookup limit—you make the DNS changes yourself. See your senders with DMARC Reporting →
How Managed SPF works
Add your domain
Add your domain to mxio. We parse your current SPF record, resolve every include chain, and show you the full lookup tree.
Point one DNS record
Replace your current SPF `include:` with a single `include:abc123.spf.mxdns.io` — a hostname unique to your domain. One record. We manage everything behind it.
We keep it current
mxio polls your upstream providers continuously. When Google, SendGrid, or Mailchimp changes their IP ranges, we update the flattened record automatically — before your mail breaks.
What's included
Stays under 10 lookups
RFC 7208 permits 10 DNS lookups per SPF evaluation. One `include:` to mxio uses one of those 10. Everything else is pre-resolved to IP ranges, no matter how many senders you have.
Automatic polling
Upstream providers change their IP ranges without notice. mxio detects those changes and republishes your SPF record within hours — not after a bounced email tips you off.
Full include tree
See every include, mechanism, and IP in your current SPF record expanded into a readable tree. Understand exactly what you're authorizing before you flatten it.
Change history
Every time the flattened record is updated, mxio records what changed and why. Audit trail for compliance, debugging, and "who changed this?" moments.
Works with any DNS provider
Your domain can be hosted anywhere — Cloudflare, Route 53, GoDaddy, Namecheap. You point one record at mxio. We handle the DNS on our end.
Included in domain health
Managed SPF domains get continuous health monitoring alongside flattening. SPF errors, DMARC alignment issues, and blacklist hits all surface in the same dashboard.
Available on Pro and Business
Managed SPF is included in Pro and Business. No add-on, no per-domain billing — the plan price covers it.
- 10 domains
- Every 30min health checks
- DMARC Reporting included (150k/mo)
- 25 domains
- Every 5min health checks
- DMARC Reporting included (500k/mo)
On Pro at four or more domains, mxio is cheaper than AutoSPF Plus on raw flattening — and includes monitoring, DMARC reporting, and 22 free tools at any domain count. Compare all plans →
Not sure if you need this?
Run a free SPF check on your domain. We'll show you the full lookup tree, count your DNS lookups, and flag any issues — no account needed.
Check your SPF record →Three services, one Senders list
Every mxio managed service is built on the same registry of who sends mail as your domain.
Fix your SPF — permanently
Pro plan includes Managed SPF for up to 10 domains, plus full monitoring and DMARC Reporting.
Start with Pro