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Rate Limiting: Stop Email Floods and Protect Your Server

A single compromised account can send thousands of spam emails in minutes. Without rate limiting, your server becomes a spam cannon, your IP gets blacklisted, and legitimate email stops working for everyone.

Rate limiting isn't optional—it's essential. SecZim gives you granular control over email flow to protect your infrastructure and reputation.

The Flood Scenario

An employee clicks a phishing link. Their credentials are stolen. Within an hour, attackers send 50,000 spam emails through your server. By the time you notice, your IP is on every blacklist in existence. Recovery takes weeks.

What Rate Limiting Protects Against

  • Compromised accounts being used for spam
  • Brute force attacks against your SMTP server
  • Email floods that crash your server
  • Reputation damage from bulk spam sending
  • Resource exhaustion during attack campaigns

SecZim's Flexible Quota System

Set limits based on any combination of sender, recipient, domain, or IP address. Configure different limits for different time windows.

Per Sender Limits

Limit how many emails each user can send

100/hour

Per Recipient Limits

Protect mailboxes from being flooded

50/hour

Per Domain Limits

Control email volume by domain

1000/day

Per IP Limits

Block aggressive senders by IP

200/hour

Real-World Scenarios

Marketing sends newsletter to 5,000 subscribers ALLOWED

Marketing department is whitelisted with higher limits. Email flows normally.

Compromised account tries to send 10,000 emails BLOCKED

After 100 emails, rate limit triggers. Remaining 9,900 emails rejected. Alert sent to admin.

External IP hammers your server with connections BLOCKED

IP limit exceeded after 200 attempts. All further connections rejected. IP auto-blacklisted.

Intelligent Rate Limiting Features

Sliding Window Counters

Instead of hard resets every hour, SecZim uses sliding windows for smoother, more accurate rate limiting. No more "burst at midnight" exploits.

Whitelist Exceptions

Trusted senders, internal systems, and high-volume legitimate users can be whitelisted to bypass rate limits entirely or get custom higher limits.

Automatic Escalation

When someone hits rate limits repeatedly, SecZim can automatically escalate to temporary blocks or permanent blacklisting. Bad actors get progressively harsher treatment.

Integration with Auto-Blacklist

Rate limit violations feed directly into SecZim's reputation system. Repeat offenders are automatically blacklisted, creating a self-defending email infrastructure.

Performance at Scale

SecZim's rate limiting uses Redis for sub-millisecond counter operations. Even at 10,000+ emails per minute, rate checks add zero perceptible latency.

  • Redis-backed atomic counters
  • Distributed-ready for multi-server setups
  • No database bottlenecks
  • Instant enforcement, no delays

Take Control of Your Email Flow

Stop worrying about compromised accounts and email floods. SecZim's rate limiting protects your server automatically.

Start Free Trial

Easy Configuration, Powerful Results

Set up rate limits in seconds through SecZim's web dashboard. No configuration files to edit, no server restarts required. Changes take effect immediately.

Your email server is only as secure as its limits. Set them wisely with SecZim.