Do you see your mail account in the Folder Pane and all of it's folders and do they contain emails ?

Do you mean you cannot download new mail ? Can you send emails ?

Do you have an Imap or Pop mail account ? How to find out if unsure...

• Account Settings
• select 'Server Settings' for the account.
• Look top right for 'Server Type' and you will see either 'Imap Mail Server' or 'Pop Mail Server'

If it's an IMAP mail account what quota limit have you reached ? In Folder Pane

• Right click on imap mail account 'Inbox' folder and select 'Properties'
• Select the 'Quota' tab to see information.

It would be useful to know current set up so we can advise if something is wrong. In Thunderbird

• Help > Troubleshooting Information
• scroll down to 'Mail and News Account' section
• Copy all the information/data in that area and paste it into this forum.

If Thunderbird has been accessing the server and auto downloading emails then it's likely you had Thunderbird remember your passwords.

• Settings > Privacy & Security
• Scroll down to Passwords section
• clickon 'Saved Passwords' button
• Clickon 'Show Passwords' button

If you see a 'Windows SEcurity' pop up window asking for password you may ask what password it it wanting? It means - when you start up computer and it asks you to Enter password to access desktop - that is the password it wants.

If account is Imap You need to use the imap://account... password If account is Pop You need to use the mailbox://account...password.

You might not be able to download emails because there is no room on the server. Basically server is not receiving new mail so Thunderbird cannot download something that does not exist. But you would need to access your webmail account to find out if there are new mail. Access your webmail account via a browser using the password you found in Thunderbird. If it does not work, you will see a 'forgotten password' link which you have to use and then follow instructions to get access to your webmail account.

If you were using a POP mail account : If there are no new emails in webmail account, then nothing can get downloaded. Delete all the very old mail - after all you should have a copy on computer in profile. Empty the server Spam folder. Empty the server TRash folder. This should free up some space on server, so new mail can be received.

If you were using an IMAP mail account : If there are no new emails in webmail account, then nothing can get downloaded. Please note: Anything you delete from webmail account will get deleted from an imap account, because imap accounts can only show whatever is on the server. So be careful what you delete. Empty the server Spam folder and Empty the Server TRash.

IF in Thunderbird, the Inbox Properties Quota said it was full, then you need to fix in Thunderbird. Copy important emails into a suitably named folder in 'Local Folders' mail account. Please double check you can still read that copied email. If copy is good then delete the original from the Imap folder. Repeat for all important emails. Finally... Right click on imap folder and select 'Compact' to remove all the old traces of moved emails from file. This should free up some space. You can check how much space is available via Properties > Quota.

The first comment above is all about getting information about the set up so we offer further advise. It's also checking to see if issue is because there are no emails on server - which in turn is caused by you using up all the allowed space.

Sometimes servers change settings and if you are not up to date then things stop working. The requested information will allow us to check you are using the correct settings for the server.

If you are getting any error pop up messages then please tell us about that error message. Best option is to post an image of the error message OR type word for word the exact error message and make sure there are no typos.