invalid APPEND command syntax, invalid data syntax.

[Ozoak]

In the past 2 weeks, when I intend to move an incoming/outgoing Email to a local folder for storing, I got the the flwg message: "The current command did no succeeded. The mail server for account ...@bredband.net responded: invalid APPEND command syntax, invalid data syntax."
What to do?

[DanRaisch]

How is the account set up in Thunderbird, as POP or IMAP? Find out using menu path Tools->Account Settings->Server Settings->Server Type at the top right of the dialogue.
Does the same thing occur if you launch the application in Mozilla Safe Mode? http://kb.mozillazine.org/Safe_mode

[Ozoak]

How is the account set up in Thunderbird, as POP or IMAP? Find out using menu path Tools->Account Settings->Server Settings->Server Type at the top right of the dialogue.
Does the same thing occur if you launch the application in Mozilla Safe Mode? <!-- m --><a class="postlink" href="http://kb.mozillazine.org/Safe_mode">ht ... fe_mode</a><!-- m -->

Tks yr comments. Up to end august, no problems at all. It started quite suddenly. Server Type: IMAP Mail Server
Again, what to do it?
/ Ozoak

[DanRaisch]

Does the same thing occur if you launch the application in Mozilla Safe Mode? http://kb.mozillazine.org/Safe_mode

[lrunet]

I have a similar problem with the same provider, bredband.net. It seems like the communication between synchronized folders is not working. E.g. when I try to send a mail I get the same error message as above and it seems like the mail is not sent. In reality it is sent but Thunderbird fails to save a copy in the Sent folder. When I change from saving in the synchronized Sent folder to a local folder it works perfect. But this is not a solution for me as the IMAP functionality is lost and I can no longer see the sent messages (in this case) in other devices. Another example of a functionality that is now lost is the search function wich is no longer working over multiple folders.
Outlook has not these problems and neither my Android phone. Does anyone have ideas on how to fix this i Thunderbird?

[telzey]

I'm having a similar but slightly different problem. My provider is Yahoo. I have two Yahoo accounts configured in Thunderbird, but I'm only having a problem with one of them. Only Inbox is affected; the other folders work fine.

When there are new messages in my Inbox, TB seems to detect them, but can't download them. The error message that I get is:

"The current operation on 'Inbox' did not succeed. The mail server for account xxxxx@yahoo.com responded: [UNAVAILABLE] UID FETCH Server error while fetching messages."

TB version is 52.3.0. I have tried restarting in Safe Mode, and it made no difference. Both the working and non-working accounts are set up as IMAP.

[k_no_uta]

I'm having a similar but slightly different problem. My provider is Yahoo. I have two Yahoo accounts configured in Thunderbird, but I'm only having a problem with one of them. Only Inbox is affected; the other folders work fine.

When there are new messages in my Inbox, TB seems to detect them, but can't download them. The error message that I get is:

"The current operation on 'Inbox' did not succeed. The mail server for account xxxxx@yahoo.com responded: [UNAVAILABLE] UID FETCH Server error while fetching messages."

TB version is 52.3.0. I have tried restarting in Safe Mode, and it made no difference. Both the working and non-working accounts are set up as IMAP.

I have the exact same problem as you. I have 4 yahoo accounts and only one of them has this issue. The other two are perfectly fine!

[DanRaisch]

telzey and k_no_uta, how is the account set up in Thunderbird, as POP or IMAP? Find out using menu path Tools->Account Settings->Server Settings->Server Type at the top right of the dialogue.

[telzey]

Both my working and non-working Yahoo accounts are set up as IMAP.

[lrunet]

I still have the same IMAP-problem as described above, sending and saving in synchronized Sent folder doesen't work. Search function works now after deleting the account an setting it up again (as recommended by my provider bredband.net).