Technology Explained

Thunderbird Can’t Send or Receive Emails? Here’s How to Fix It

October 7, 2025

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5 minute read

If you’re using Mozilla Thunderbird as your email client, you probably rely on it daily to send and receive important messages. But sometimes, users run into frustrating issues where Thunderbird simply can’t send or receive emails. Whether it’s a sudden error, account misconfiguration, or server-related issue, this problem can disrupt your workflow.

In this detailed guide, we’ll walk you through the most common causes and proven solutions of Thunderbird Email Troubleshoot. If you need quick assistance, you can always contact expert support at +1–872–666–1966 for immediate troubleshooting help.

Why Thunderbird Won’t Send or Receive Emails

Before we dive into the fixes, it’s important to understand the root causes. Thunderbird relies on your email provider’s server settings, local system configuration, and internet connection to function properly. Here are some of the most common reasons why you may face this issue:

Incorrect Server Settings
- Wrong IMAP/POP or SMTP settings often prevent Thunderbird from syncing with your email server.
Authentication Errors
- If your username, password, or security protocol (SSL/TLS) is not set correctly, Thunderbird won’t log in.
Firewall or Antivirus Blocking
- Security software can sometimes block Thunderbird’s connection to email servers.
Outdated Thunderbird Version
- Running an old version of Thunderbird may cause compatibility issues with email providers.
Corrupt Profile or Inbox Folder
- If your Thunderbird profile data is corrupted, you might not be able to send or receive emails.
Server Downtime
- Occasionally, the issue may not be with Thunderbird but with your email provider’s servers.

How to Fix Thunderbird When It Can’t Send or Receive Emails

Let’s go step by step and troubleshoot the problem.

1. Check Your Internet Connection

It may sound obvious, but the first thing you should verify is your internet connection. If your connection is weak or disconnected, Thunderbird won’t be able to send or receive emails.

Restart your router.
Try accessing a website to confirm connectivity.
Switch to a different network if possible.

2. Verify Incoming and Outgoing Server Settings

Incorrect IMAP/POP3 or SMTP settings are the most common culprits. Double-check with your email provider and ensure the following:

IMAP/POP Settings (for incoming mail):
- Server Name: e.g., imap.gmail.com or pop.gmail.com
- Port: IMAP usually uses 993 with SSL/TLS; POP3 usually uses 995
- Authentication: Normal password
SMTP Settings (for outgoing mail):
- Server Name: e.g., smtp.gmail.com
- Port: 465 (SSL/TLS) or 587 (STARTTLS)
- Authentication: Normal password

If you’re unsure, call +1–872–666–1966 for guided help setting up your Thunderbird account correctly.

3. Check Your Username and Password

If Thunderbird repeatedly asks for your password or shows an authentication error, do the following:

Log in to your email account via a web browser to confirm your credentials.
If your provider uses two-factor authentication (2FA), you may need to generate an app password specifically for Thunderbird.

4. Update Thunderbird to the Latest Version

An outdated version of Thunderbird may not support the latest security protocols used by email providers.

Open Thunderbird.
Go to Help > About Thunderbird.
If an update is available, install it and restart Thunderbird.

5. Disable Firewall or Antivirus Temporarily

Sometimes, your firewall or antivirus software mistakenly blocks Thunderbird’s outgoing or incoming connections.

Temporarily disable your antivirus/firewall and test if Thunderbird works.
If it does, add Thunderbird as an exception in your security software.

6. Repair Corrupt Folders

Corruption in the Inbox or Sent folder may prevent Thunderbird from loading or sending emails.

Right-click on the folder (Inbox, Sent, Drafts, etc.).
Select Properties > Repair Folder.
Restart Thunderbird.

If the profile itself is corrupt, you may need to create a new Thunderbird profile and reconfigure your account.

7. Check Email Provider’s Server Status

Sometimes, the issue is not on your side. Email providers like Gmail, Yahoo, or Outlook may have temporary outages.

Visit your provider’s status page or check via a web browser.
If the server is down, you’ll need to wait until it’s back online.

8. Clear Outbox and Message Filters

If you’re unable to send emails, check your Outbox. Sometimes stuck messages block all outgoing mail.

Delete or move messages stuck in Outbox.
Review any filters or rules that may be incorrectly redirecting your emails.

9. Reconfigure Your Email Account in Thunderbird

If nothing else works, try removing and re-adding your account.

Go to Account Settings > Account Actions > Remove Account.
Restart Thunderbird.
Add your account again using correct IMAP/POP and SMTP settings.

10. Contact Expert Thunderbird Support

If you’ve tried all the above solutions and Thunderbird still won’t send or receive emails, it’s time to get expert help.

Call +1–872–666–1966 to speak with a support specialist who can diagnose the issue quickly and get your Thunderbird back up and running.

Preventive Tips for Thunderbird Users

Always keep Thunderbird updated to the latest version.
Regularly back up your Thunderbird profile to avoid data loss.
Use IMAP instead of POP for better synchronization across devices.
Periodically clear your Thunderbird cache and compact folders.
Ensure your antivirus/firewall software is configured correctly.

Final Thoughts

Facing an issue where Thunderbird can’t send or receive emails can be stressful, especially when you rely on it for work or personal communication. The good news is that most problems are caused by incorrect settings, minor software glitches, or temporary server outages — all of which can be fixed with the solutions above. If you need step-by-step guidance or your issue is more complex, don’t waste time troubleshooting endlessly. Just call the Thunderbird support helpline at +1–872–666–1966 and get immediate assistance from experts.

Stay connected, and keep your Thunderbird running smoothly!

Thunderbird Email Troubleshooting FAQs

1. Why can’t I send emails from Thunderbird?

Possible causes:
- Incorrect SMTP server settings
- Authentication issues (wrong username/password)
- Port or encryption mismatch
- Firewall or antivirus blocking outgoing mail

Fix: Double-check your SMTP settings under Account Settings > Outgoing Server (SMTP). Ensure the server name, port, and security settings match your email provider’s recommendations.

2. Why am I not receiving emails in Thunderbird?

Possible causes:
- POP/IMAP server misconfiguration
- Connection issues with the mail server
- Filters or junk settings moving emails
- Antivirus or firewall interference
Fix: Verify your incoming server settings (IMAP or POP) and check your internet connection. Also, inspect your spam/junk folders and disable overly aggressive filters.

3. How do I check if Thunderbird is connecting to the mail server?

Go to Tools > Activity Manager to view recent connection attempts.
Use Help > Troubleshooting Information to see logs and error messages.

4. What should I do if I get a ‘Login to server failed’ error?

Fix: Re-enter your password when prompted or update it via Settings > Passwords > Saved Passwords. If you’ve recently changed your email password, Thunderbird may still be using the old one.

5. How can I fix ‘Connection to server timed out’ errors?

Fix: Increase the timeout settings in Config Editor (mailnews.tcptimeout) or check for network/firewall issues. Also, ensure your antivirus isn’t scanning Thunderbird’s connections.

6. Why does Thunderbird say ‘Sending of the message failed’?