Thunderbird SMTP - ImprovMX Guides

This guide explains how to configure ImprovMX SMTP with Mozilla Thunderbird to send emails from your custom domain alias.

Prerequisites

Before starting, you must:

Create SMTP credentials in the ImprovMX Dashboard
Add DKIM and DMARC records to your DNS configuration
Have a Premium or Business membership to access SMTP features

Step 1: Configure the SMTP Server

Access Thunderbird's account settings through Tools → Account Settings, then navigate to the Outgoing Server (SMTP) tab and select Add.

Server Configuration

Description: Any label you prefer (e.g., "ImprovMX")
Server name: smtp.improvmx.com
Port: 587 or 465
Connection security: STARTTLS (for port 587) or SSL/TLS (for port 465)
Authentication method: Normal Password
Username: Your ImprovMX alias address (e.g., you@yourdomain.com)

Step 2: Create an Identity

Within Account Settings, select your email account, choose Manage Identities (at the bottom of the page), then click Add.

Enter these details:

Email Address: Your ImprovMX alias
Outgoing Server: The SMTP server configured in Step 1

Step 3: Send a Test Email

Compose a new message
Select your alias in the From field
Enter a recipient, subject, and test content
Send the message
Authenticate using your ImprovMX SMTP password when prompted

Tip: You can optionally save your password to avoid entering it each time you send.

Adding More Aliases

You can now send emails through your alias via Thunderbird. Repeat these steps for additional aliases you want to configure.