Cleanbox vs ImprovMX - Email Forwarding vs Full Inbox Protection

ImprovMX and Cleanbox both handle email for custom domains, but they approach the problem from opposite directions. ImprovMX is a focused email forwarding tool — point your MX records at it, and it delivers email to your chosen inbox. Cleanbox is an inbox protection platform that includes forwarding, filtering, alias management, and more.

This is an honest comparison. We will tell you where ImprovMX is the better choice.

Quick comparison

	Cleanbox	ImprovMX
Core focus	Inbox protection + aliases	Email forwarding for domains
Forwarding	Yes (aliases + Relay)	Yes (primary feature)
SMTP sending	No	Yes (send as your domain)
Spam filtering	Yes (Rspamd + AI + reputation)	Basic (toggle on/off)
Virus scanning	Yes (ClamAV)	No
Contact management	Yes	No
Shield (rate limit/schedule)	Yes	No
Custom domains	Premium+ (from $15/mo)	Free (1 domain)
Free tier	3 aliases on shared domain	1 domain, 25 aliases, no SMTP
SMTP outbound	No	Yes (paid plans)
API	Yes	Yes
Catch-all	No	Yes

Where ImprovMX wins

SMTP sending

ImprovMX lets you send email as your custom domain address. Set up their SMTP credentials in Gmail, Outlook, or any email client, and replies appear to come from you@yourdomain.com. Cleanbox is receive-only — it processes incoming email but does not offer outbound sending.

If you need a complete email solution for a custom domain (receive + send) without running your own mail server, ImprovMX handles both directions.

Free custom domain forwarding

ImprovMX’s free tier includes one custom domain with 25 aliases. Cleanbox’s free tier only offers aliases on the shared @cleanbox.me domain — custom domains require the Premium plan at $15/month. For basic custom domain email forwarding on a budget, ImprovMX is significantly cheaper.

Catch-all addresses

ImprovMX supports catch-all forwarding: any email sent to anything@yourdomain.com is forwarded to your inbox, even if the specific alias does not exist. This is convenient for catching emails sent to misspelled addresses or addresses you forgot to create. Cleanbox does not support catch-all forwarding.

Simplicity

ImprovMX does one thing well: forward email from your domain to your inbox. The setup takes two minutes (add MX records, configure forwarding), and there are no complex features to learn. If all you need is "email to my domain goes to my Gmail," ImprovMX is the simpler tool.

Provider-specific DNS guides

ImprovMX publishes detailed DNS setup guides for 20+ domain registrars and hosting providers. This makes setup straightforward regardless of where your domain is registered.

Where Cleanbox wins

Spam filtering

This is the core difference. ImprovMX has a basic spam filter toggle, but spam detection is not its focus. Cleanbox processes every email through a dedicated detection stack: Rspamd scoring, DNSBL checks, SPF/DKIM/DMARC authentication, ClamAV virus scanning, and AI classification. The result is significantly fewer spam and phishing messages reaching your inbox.

If you use ImprovMX, spam filtering depends entirely on your destination provider (Gmail, Outlook, etc.). If you use Cleanbox, you add a specialized filtering layer regardless of where your email is delivered.

Contact management

Cleanbox automatically categorizes every sender and lets you set contact states (whitelist, block, mute, prioritize). These states affect future email handling. ImprovMX does not track or manage contacts — it simply forwards everything to your inbox.

Shield protection

Cleanbox Shield lets you rate-limit senders, schedule delivery windows, and enable sender approval per alias. These features do not exist in ImprovMX or most other forwarding services.

MX relay for existing servers

If you already run a mail server, Cleanbox Relay acts as an MX relay — filtering email before forwarding to your server. ImprovMX is a forwarding service, not a relay. It does not sit in front of existing mail infrastructure.

Per-alias spam thresholds

In Cleanbox, each alias can have its own spam score threshold. A public-facing info@ alias can have a lenient threshold while a personal alias is strict. ImprovMX applies the same filtering (on or off) to all aliases on a domain.

Pricing comparison

Need	Cleanbox	ImprovMX
Basic forwarding (1 domain)	$15/mo (Premium)	Free
Forwarding + sending	Not available	$9.99/mo (Premium)
Forwarding + spam filtering	$15/mo (Premium)	Not available
Multiple domains	$35/mo (Advanced, 10 domains)	$9.99/mo (Premium, 10 domains)
MX relay for mail server	$35/mo (Advanced)	Not available

ImprovMX is cheaper for pure forwarding. Cleanbox costs more but includes features ImprovMX does not offer at any price tier.

When to choose ImprovMX

• You need both sending and receiving on a custom domain without running a mail server
• You want free custom domain forwarding
• You need catch-all addresses
• You want the simplest possible setup — just forwarding, nothing else
• Your email provider’s spam filter (Gmail, Outlook) is good enough for your needs

When to choose Cleanbox

• You want spam filtering before delivery, not just forwarding
• You need contact management, Shield, or per-alias thresholds
• You run a mail server and need MX relay protection
• You want virus scanning on every incoming email
• You need all-in-one inbox protection, not just a forwarding pipe

Can you use both?

In theory, yes — but it creates routing complexity. A more practical setup: use ImprovMX for outbound sending (its SMTP service) and Cleanbox for inbound filtering (its Relay or alias service). This gives you two-way custom domain email with Cleanbox’s filtering on the inbound side.

For a broader comparison of forwarding services, see Email Forwarding Services Compared. For how Cleanbox compares to other alias-focused services, see Cleanbox vs SimpleLogin and Cleanbox vs addy.io.