Getting started

What’s New

Roadmap

Octeth Training Program

Installation & Setup

Requirements

Architecture

Server Setup

Oempro Installation

Community Edition Install

SSL Certificates

Version Upgrade

Troubleshooting

Video Tutorials

Administration

Quick Walkthrough

Security

Sub Admin Accounts

Settings

Delivery Servers

Global Segments

Global Custom Fields

Bounce Processing

Spam Complaints

Suppression List

Plug-Ins

Delivery Report

User Management

Maintenance

Audience Management

Introduction

Subscriber Lists

Custom Fields

Segments

Subscribers

Webhooks

Website Event Tracking

Email Marketing

Introduction

Auto Responders

Email Campaigns

Sender Domain Man.

Journeys (Automation)

Bounce Processing

Email Personalization

FBL Processing

Email Builder Integrations

Email Deliverability

Sender Domain Management

Plug-Ins & Add-Ons

AI Plug-In

RSS Plug-In

Bounce Catcher Add-On

Link Proxy Add-On

Developers

Introduction

Single Sign On

API

Plug-In Development

Database

Advanced

Reverse Proxy

Cookbook

Help

Troubleshooting

How to activate TLS for Octeth Email Gateway Inbound SMTP Server

Octeth has a powerful, high-performance inbound SMTP server for the Email Gateway feature. This SMTP server accepts TLS connections as well. In order to activate TLS with a properly setup SSL certificate, follow these steps.

First, initiate your SSL certificate using Let’s Encrypt or other SSL certificate providers.

SSH into the oempro-app container:

cd /opt/oempro/
docker exec -ti oempro_app bash

Edit /var/www/html/_dockerfiles/inbound-smtp-server/server.key and set the file content to the private key of the new SSL certificate.
Edit /var/www/html/_dockerfiles/inbound-smtp-server/server.crt and paste the new (1) SSL certificate first, then (2) paste the CA bundle of the SSL certificate.
Edit /var/www/html/_dockerfiles/inbound-smtp-server/config.json and paste these two file paths to Certificate and PrivateKey parameters. Paths must be relative. Here’s an example:

{
  "Debug": false,
  "Listen": [
    ":25"
  ],
  "AppName": "Oempro SMTP Server",
  "Hostname": "test.local",
  "AdminAPIKey": "3b3c98-****-****-****-d3bb6b",
  "EmailMaxSizeKB": 100,
  "SMTPTimeout": 15,
  "Certificate": "./server.crt",
  "PrivateKey": "./server.key",
  "MaxConnectionLimit": 1500,
  "LogFiles": {
    "Connections": "./log_connections.log",
    "Authentications": "./log_authentications.log"
  },
  "OemproAPIUrl": "http://192.168.99.101/api.php"
}

Rebuild and re-delpoy the inbound SMTP server:

cd /opt/oempro/
docker-compose build oempro_emailgateway_inbound_smtp
docker-compose kill oempro_emailgateway_inbound_smtp
docker-compose up -d oempro_emailgateway_inbound_smtp

Test the TLS connection:

openssl s_client -quiet -starttls smtp -connect your.smtp-server.com:25 # (or 587)

depth=2 C = BE, O = GlobalSign nv-sa, OU = Root CA, CN = GlobalSign Root CA
verify return:1
depth=1 C = BE, O = GlobalSign nv-sa, CN = AlphaSSL CA - SHA256 - G2
verify return:1
depth=0 CN = *.sendlayer.net
verify return:1
250 ENHANCEDSTATUSCODES
ehlo local
250-smtp.sendlayer.net greets local
250-SIZE 307200
250-AUTH LOGIN PLAIN
250 ENHANCEDSTATUSCODES
quit
221 2.0.0 your.smtp-server.com Octeth SMTP Server v1.2 ESMTP Service closing transmission channel
read:errno=0

⚠️

IMPORTANT: server.crt file must contain the certificate first and then the CA bundle. server.key file must contain the private key only.

The server.crt file structure:

-----BEGIN CERTIFICATE-----
...
****************************************************************
****************************************************************
...
-----END CERTIFICATE----- 

-----BEGIN CERTIFICATE-----
...
****************************************************************
****************************************************************
...
-----END CERTIFICATE-----

The server.key file structure:

-----BEGIN PRIVATE KEY-----
...
****************************************************************
****************************************************************
...
-----END PRIVATE KEY-----

On this page

How to activate TLS for Octeth Email Gateway Inbound SMTP Server

💠

Homepage Customer Area Community Portal Contact Us

Twitter

How to activate TLS for Octeth Email Gateway Inbound SMTP Server

How to activate TLS for Octeth Email Gateway Inbound SMTP Server

Footer Social Icons