Overview

This guide walks you through adding your email account to Mozilla Thunderbird using IMAP. IMAP keeps your messages synchronized between the server and all your devices, so anything you read, send, or file in Thunderbird is reflected everywhere else you check your mail.

Before you begin

Have the following ready:

• Thunderbird installed on your computer. If you don’t have it yet, download it from thunderbird.net.
• Your full email address (for example, yourname@usgo.net)
• Your email account password

Server Settings (Quick Reference)

Use these settings any time Thunderbird asks for server information.

IMAP — Incoming Mail

SMTP — Outgoing Mail

Step 1 — Open the Account Setup Wizard

1. Launch Thunderbird.
2. Click the menu button (three horizontal lines, upper-right) and choose Account Settings.
3. At the bottom of the left sidebar, click Account Actions → Add Mail Account.

Tip: If this is the first time you’ve opened Thunderbird, the Account Setup screen will open automatically — skip to Step 2.

Step 2 — Enter Your Account Details

1. Your full name — the name your recipients will see (for example, “Jane Smith”).
2. Email address — your full email address (for example, yourname@usgo.net).
3. Password — your email account password. Check Remember password if you don’t want to enter it each time.
4. Click Continue.

Thunderbird will attempt to auto-detect the server settings. If it succeeds, choose IMAP (remote folders) and click Done. If the detected settings don’t match the table above, or if auto-detect fails, click Configure manually and continue to Step 3.

Step 3 — Enter the Server Settings Manually

Fill in the form using the values below:

Incoming Server

• Protocol: IMAP
• Hostname: mail.usgo.net
• Port: 993
• Connection security: SSL/TLS
• Authentication method: Normal password
• Username: your full email address

Outgoing Server

• Hostname: mail.usgo.net
• Port: 465
• Connection security: SSL/TLS
• Authentication method: Normal password
• Username: your full email address

Click Re-test to verify the settings, then click Done.

If Thunderbird shows a security warning about the certificate, confirm that the hostname is spelled correctly. If it is, you can accept the certificate to continue.

Step 4 — Confirm the Account Is Working

1. Your new account should now appear in Thunderbird’s folder pane on the left.
2. Click Get Messages in the toolbar — your Inbox should populate.
3. Send a test message to yourself (or to another address you can check) to confirm both sending and receiving are working.

Step 5 (Optional) — Subscribe to Server Folders

Thunderbird may not automatically show every IMAP folder on the server (such as Sent, Drafts, Junk, and Trash). To choose which folders are visible:

1. Right-click your account name in the folder pane.
2. Choose Subscribe…
3. Check the boxes for the folders you want to see.
4. Click OK.

Step 6 (Optional) — Map Special Folders

To make sure sent mail, drafts, and deleted items are saved on the server (so they appear on your phone and webmail too):

1. Open Account Settings for your email account.
2. Click Copies & Folders.
3. Under When sending messages, automatically, choose Other and select the Sent folder on the server.
4. Under Drafts and Templates, choose Other and select the Drafts folder on the server.
5. Click Server Settings in the left sidebar, then under When I delete a message, choose Move it to this folder and select Trash on the server.

Troubleshooting

“Cannot connect to incoming server” or login fails repeatedly

• Double-check that your username is your full email address, not just the part before the @.
• Confirm your password by signing in to webmail. If webmail works but Thunderbird doesn’t, the password is correct and the issue is in Thunderbird’s settings.
• Make sure connection security is set to SSL/TLS and authentication method is Normal password.

“Cannot send mail” / messages stuck in Outbox

• Open menu → Account Settings → Outgoing Server (SMTP), select your outgoing server, and click Edit to confirm the hostname, port (465), and SSL/TLS settings match the table above.
• Some Internet providers block port 465. If you suspect this, try a different network (such as a mobile hotspot) to confirm. Contact our support team if the issue persists.

Folders look wrong or are missing

• Use the Subscribe… menu (Step 5) to enable the folders you want visible.
• If sent mail isn’t appearing on your other devices, repeat Step 6 to map the special folders to the server.

Thunderbird keeps prompting for a password

• Open menu → Settings → Privacy & Security → Saved Passwords, remove any outdated entries for mail.usgo.net, then re-enter the password and check Remember password.

Need More Help?

If you’ve completed these steps and are still unable to connect, please contact our support team and include:

• The exact error message you’re seeing (a screenshot is ideal)
• Your email address (never your password)
• The version of Thunderbird you’re using (menu → Help → About Thunderbird)