GreenArrow Engine
Change Log
- Historic (Pre-4.200.0) Change Log
Getting Started
- GreenArrow Concepts
- Hardware Requirements
- Supported Linux Distributions
- SSH Access
- Co-Existing With Other Software
- Firewall Configuration
- Installation Guide
FAQs
- Chrome Mixed Content Compatability Guide
- GreenArrow Engine and AWS
- Common Error Messages
- Message Delivery
- Modifications and Customizations
- Pausing and Dumping Queues
- Direct Database Access
- Getting Started with Email Injection
- Creating a Drop Route
- Time Zones
- First Steps after Install
- GreenArrow Components
- Logging SMTP Sessions in GreenArrow
Configuration
- Configuration File
- General Settings
- Performance Tuning
- Adding a New Domain
- Adding a New IP Address
- Adding A New Whitelabeled Cloud Domain
- IPs Authorized to Relay
- License Key
- URL Domains
- Convert PowerMTA® Configuration
- Secret Constants
- Processing Events on Dedicated Servers
- Managing GreenArrow Monitor SeedList
- Proxy Protocol
- Replace Content Domain
- Link Replacements
User Management
- Two-Factor Authentication
- Users for Email Injection
Email Authentication
- DKIM
- SPF and Sender ID
- Configuring a New From Address Domain
- Email Authentication for ESPs
Injecting Mail
- SimpleMH Injection
- Raw Injection
- - Raw Injection Headers
  - PHPMailer Raw Injection Example
- Injecting Mail with HTTP Submission API
- Local Injection Options
- Message Archive
- QMQP
- QMQP Streaming Protocol
- Speed Considerations
- Obscured Email Addresses
Delivering Mail
- VirtualMTAs
- Throttling
- - Updating Throttle Settings on the Command Line
  - Updating Throttle Settings in SQL
- Dynamic Delivery
- Retry Schedule
- Internal DNS Cache
- Recipient MX Selection
- Pausing Domains
Incoming Email
- Incoming Email Domains
- Aliased Incoming Email Domains
- Bounce Mailboxes
- Spam Complaint Mailboxes
- Email Forwarders
- SMTP AUTH and POP3 Email Users
- DNSBLs and RBLs
Bounces and Spam Complaints
- Bounce Processor Concepts
- Bounce Processor Configuration
- Spam Complaint Processor
- Feedback Loops
- - Yahoo's transition from ReturnPath
- Lite Bounce Processor
Reporting
- Send Statistics Overview Page
- Send Statistics Pages
- Send Statistics Integration
- Dynamic Delivery Statistics
- Disk Queue Summary
- Stats API
- Local Delivery Attempt Status Messages
- Remote Delivery Attempt Error Messages
- hvmail_report Command
- Delivery Attempt Log (Deprecated)
- Delivery Attempt Message Formats
- Delivery Event Processed Logfile Format
- Remote Delivery Status Log
- hvmail_generate_email_report Command
- hvmail_get_possible_spamtrap_hits Command
- Service Logs
- GreenArrow Status Command
- Remote Connections
- Disk Queue Messages
Event Notification System
- Types of Events
- Events Table Maintenance
- Event Processor
- Legacy Event Notification
GreenArrow Cluster
- GreenArrow Proxy
- GreenArrow Configuration
- Cooperative Throttling
- SMTP Connection Proxying
- Troubleshooting
Network Services
- HTTP Server
- PostgreSQL
- POP3 Server
- SMTP Services
- Disabling SMTP-AUTH Username Logging
- TLS Certificate Configuration
- TLS Encryption for SMTP
- Legacy Services
- - Legacy Recursive DNS Server
Server Management and Backups
- Administering GreenArrow Without root Access
- GreenArrow Updates
- GreenArrow Downgrades
- Convert CentOS to Alma Linux
- Debian Updates
- PostgreSQL 16 Update
- Server Management
- System Administration
- Persistence Path Mode
- Managed Backups
- Unmanaged Backups
- Restoring Backups
- - Recover from Database Corruption
- Server Migrations
- Server Monitoring
- StatsD Integration
- fail2ban Integration
- Stopping and Starting GreenArrow Engine
- greenarrow Command
- hvmail_init Command
- Bounce Recovery
- - December 2020 Gmail Outages
- Disk Usage
- - Delete SimpleMH Clicks and Opens
- Troubleshooting Disk Space Issues
- Moving GreenArrow to a New Partition
- Email Address Retention
- High Availability Cluster
- - High Availability Cluster Administration
  - Self Managed High Availability Clusters
APIs
- Stats API
- - Send Status API
  - Disk Queue Summary API
- HTTP Submission API
- Configuration API
- Running Custom Code During Delivery Attempts
Third Party Integrations
- Amazon SES Integration
- Interspire Email Marketer Integration
- Ongage Integration
- SendGrid Integration
- SMTP Relay Service Integration
Support Contact Info

Internal DNS Cache

GreenArrow maintains an internal DNS cache that it uses to speed up message delivery. Here are some of its attributes:

It’s always on and is only accessible by GreenArrow.
It does not conflict with other DNS servers, such as BIND.
It does not have any configurable settings.
It caches DNS records for a maximum of 6 minutes, so if an upstream resolver problem is fixed or a DNS record is changed, it may take up to 6 minutes for the internal cache to attempt a new lookup.
It is a completely separate system from the Legacy Recursive DNS Server.

Retry Schedule

Recipient MX Selection