Blog & Resources
Client Panel
TR EN
PITBULL SECURE GATEWAY
Blog & Resources

Products

Pitbull Secure Gateway Advanced Threat & Quarantine Outbound Filtering Smarthost SMTP Relay Features Release Notes Platform Security Analysis

Solutions

Hosting & ISP Banks & Financial Services Universities & Education ESP & High Volume Enterprise IT MSP & Reseller All Solutions Compatibility

Company

About Us Why Pitbull? Contact Our Data Center Roadmap Compare Privacy Policy Terms of Use Service Level Agreement KVKK Policy GDPR Policy
Platform Pricing Contact
Start 14-Day Free Trial

MX gateway and relay server integration for Exim environments

Pitbull MX gateway for Exim (Free, Linux/Unix) mail servers: inbound filtering, quarantine and outbound relay. Outbound traffic is directed to the Pitbull relay via Exim smarthost router.

Exim · Relay MX + Relay Server
Inbound MX ROUTED
Relay AKTİF
Filter RSPAMD
Abuse OBSERVE
Exim Relay MX Gateway Rspamd NOC
Linux/Unix
Platform
Free
License
MX+Relay
Gateway model
KVKK
Local processing

Integration challenges

Pitbull solves mail security on this platform with the MX gateway model.

Limited native filtering

Exim default spam protection is insufficient against advanced phishing and BEC attacks.

Outbound blind spot

Without relay configuration, outbound spam and abuse detection is delayed; IP reputation drops.

Missing central visibility

Hard to monitor traffic, quarantine and reject reasons from one point.

Scattered policy

Managing SPF/DKIM/DMARC and quarantine policies per server increases error risk.

Pitbull integration with Exim

In environments using Exim, Pitbull integration works on two channels:

  • Inbound: DNS MX records point to the Pitbull gateway; Rspamd-based filtering, quarantine and policy engine secure inbound traffic.
  • Outbound: Outbound traffic is directed to the Pitbull relay via Exim smarthost router.

Relay Server Configuration

Exim relay is configured via a smarthost router and SMTP AUTH credentials in /etc/exim4/passwd.client.

Inbound MX Gateway

  • Point domain MX records to the Pitbull gateway address (priority 10)
  • Rspamd spam, phishing and malware filtering at the gateway layer
  • Malicious attachment scanning via ClamAV / Avast REST
  • SPF, DKIM and DMARC checks + score breakdown
  • Suspicious messages isolated in quarantine; admin-approved release workflow

Outbound Relay Settings

To route outbound traffic to the Pitbull relay on Exim:

# /etc/exim4/exim4.conf
pitbull_smarthost:
  driver = manualroute
  domains = ! +local_domains
  transport = remote_smtp
  route_list = * [relay.pitbull.com.tr]
  port = 587
  hosts_require_auth = *
  hosts_require_tls = *

# /etc/exim4/passwd.client
*:relay.pitbull.com.tr:smtp-user@domain.com:password

This configuration passes outbound traffic through the Pitbull outbound filtering engine. SMTP Abuse Radar, per-tenant rate limits and Emergency Outbound Lockdown are activated.

Authentication

  • Add Pitbull include to SPF
  • Enable DKIM signing from Pitbull panel and publish DNS TXT record
  • Start DMARC at p=none and monitor reports

Operational Visibility

Monitor delivery rates, reject reasons, queue status and GeoIP/ASN distribution on NOC screens. Deliver periodic security summaries to management teams with executive PDF reports.

Smarthost configuration

Outbound relay and MX routing steps

Outbound — smarthost

To route all outbound traffic through Pitbull relay, add a smarthost router in Exim (/etc/exim4/exim4.conf or router section):

begin routers

pitbull_smarthost:
  driver = manualroute
  domains = ! +local_domains
  transport = remote_smtp
  route_list = * [relay.pitbull.com.tr]
  port = 587
  hosts_require_auth = *
  hosts_require_tls = *

Add SMTP AUTH credentials to /etc/exim4/passwd.client:

*:relay.pitbull.com.tr:smtp-user@your-domain.com:yourpassword

After changes: update-exim4.conf && systemctl reload exim4

Alternative: debconf smarthost

dc_eximconfig_configtype='smarthost'
dc_smarthost='relay.pitbull.com.tr::587'
dc_relay_nets=''

Run update-exim4.conf to apply.

Inbound — MX

@  IN  MX  10  mx.pitbull.com.tr.

Illustrated setup guide

Pitbull integration on this platform is completed in 4 visual steps.

Gateway flow diagram
MX Gateway
1

MX Gateway

Point DNS MX to the Pitbull gateway address.

SPF · DKIM · DMARC
2

SPF · DKIM · DMARC

Add authentication DNS records.

Outbound Relay
3

Outbound Relay

Set Pitbull relay as smarthost / relayhost.

NOC Verification
4

NOC Verification

Send a test email and verify in the NOC panel.

Setup steps

  1. 1 Point DNS MX records to the Pitbull gateway address (priority 10).
  2. 2 Add Pitbull include to SPF; generate DKIM TXT from panel and add to DNS.
  3. 3 Set the Pitbull relay address in Exim relay/smarthost settings.
  4. 4 Send a test email and verify inbound/outbound traffic in the NOC panel.
  5. 5 Start DMARC at p=none and monitor aggregate reports.
Back to all integrations