Products & Service

Mail Transfer Agent for large-scale mail delivery

It is a highly flexible and secure mail system that can handle a wide range of applications from large to small.

Halon MTA is a high-speed mail delivery system (MTA) that supports both sending and receiving mail. In addition to the essential functions for sending and receiving emails, customizable scripts and abundant libraries make it possible to realize a configuration that suits your environment and requirements.

overview HALON
overview HALON

Service Features

High performance and fully featured

  • Fast delivery performance
  • Flexible queue management and control for each application using the virtual mail queue function
  • Multiple IP address settings and allocation for each application (IP address segmentation)
  • Cooperation with external API and external DB

Flexible flow control

  • Control of the number of transmissions and the number of simultaneous connections per unit time such as for each source / destination IP address, each virtual queue, and each destination domain.
  • Can be dynamically controlled according to the response (error content and number of errors) of the connection destination mail server.
  • Counter information synchronization between clusters
  • Ensuring mail reachability (mail deliverability) by various methods

Script-based workflow

  • Connect, HELO / EHLO, MAIL, RCPT, end-of-DATA, disconnect SMTP phase and script execution before and after delivery
  • Different scripts can be executed for each reception IP address and port.
  • PHP, Python-like scripting language
  • Abundant libraries are available

Supports the latest sender authentication / encryption

  • Add DKIM signature when sending
  • SPF, DKIM, DMARC verification at the time of reception
  • Supports STARTTLS, SMTPS (SMTP over TLS), MTA-STS, DANE

Outbound spam protection

  • Multiple source IP groups can be used, and different scripts can be applied to each.
  • Limit control for each destination, SPAM transmission countermeasures, delivery error handling, queue handling for each website and user
  • Prevents being registered on an external blacklist

Easy and safe introduction

  • Multiple versions can be operated in parallel, and a new workflow can be applied without affecting emails during delivery processing.
  • Visualize changes with revision management
  • Rollback support when problems occur due to revision management

Use cases

Aggregate multiple MTAs installed for each service or email type.

Halon MTA use cases




Other functions and features

Highly accurate anti-spam and anti-virus
  • SPAM / Virus filter by Cyren and Sophos
  • Compatible with filters made by other companies
  • High accuracy managed by intelligent workflow
Support for encryption standards
  • MTA-STS、TLS-RPT、DANE
  • Client certificate for server and client
  • More detailed TLS protocol
  • Cryptographic control
  • SNI(Server Name Indication)
Milter compatible
  • Allows use of third-party Milter applications, including TwoFive's developed solutions
Powerful reporting and logging
  • Script-controllable custom reports
  • Supports external linkage such as HTTP / JSON, SQL, Elasticsearch
Flexible queue management
  • Can hold and manage multiple queues by destination domain or other policy definition
  • Retry policy and number of sessions can be set and managed individually for each queue
Large scale support
  • Masterless cluster with no single point of failure
  • Centralized management by pushing settings and workflow changes
  • All servers can play the same role and is easy to expand
  • Partially separate cluster is possible according to the configuration