← Back to email help
Choose a different device or app

Desktop

Thunderbird on a computer

Use these steps if you use Thunderbird on Windows, Mac or Linux.

Step by step

Follow these steps

1

Start adding an account

Open Thunderbird. Click the three-line menu, then Add Account, then Email. If this is your first account, the setup screen may already be open.

2

Enter your name and email

Type your name and your full business email address. Click Continue.

3

Check the settings Thunderbird finds

If it cannot find the account, choose the option to configure it manually. For the account type, choose IMAP.

4

Fill in the incoming settings

Use fusion.mxrouting.net, port 993 and SSL/TLS. Use your full email address as the username.

Server name
fusion.mxrouting.net
Port
993
Security
SSL/TLS
5

Fill in the outgoing settings

Use the same server name, fusion.mxrouting.net, port 465 and SSL/TLS. Use your full email address as the username here too.

Server name
fusion.mxrouting.net
Port
465
Security
SSL/TLS
6

Enter your email password

Choose Normal password if asked how to sign in. Enter your email password when prompted. Do not choose Google or Microsoft sign-in for this account.

7

Finish and check your inbox

Complete the remaining prompts. Send an email to another account you can open, then reply to check that mail arrives.

Email settings to copy

Use these exact details

Keep this open while you fill in your email app. Select any value yourself if copying does not work.

Mail server
fusion.mxrouting.net
Incoming port (IMAP)
993
Security for incoming and outgoing mail
SSL/TLS
Outgoing port (SMTP)
465
Email sign-in website
https://fusion.mxrouting.net/roundcube/
Username
Your complete email address
Password
Your email password
Outgoing sign-in
Required

Do not enter or save a password on this guide website.

Helpful notes

Keep in mind

Thunderbird 140 ESR and older interfaces

Versions before 150 use the previous account wizard. Use Mozilla’s legacy manual-configuration guide linked below if that is what you have installed; its screenshots do not represent Account Hub.

About this guide

Version: Thunderbird 150+ · Account Hub
Documentation checked: September 18, 2026
Method: Official documentation reviewed

Sources