This site will have limited functionality while we undergo maintenance to improve your experience. If an article doesn't solve your issue and you want to ask a question, we have our support community waiting to help you at @FirefoxSupport on Twitter and/r/firefox on Reddit.

Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

Natao arisiva ity resaka mitohy ity. Mametraha fanontaniana azafady raha mila fanampiana.

TB suddenly lost all my IMAP folders; they are active on the server.

more options

I have been using TB successfully for years. I have two email accounts in my TB, one is POP & the other is IMAP. Both have been working fine, including the fact that all folders on my IMAP account have been synchronized and fully useful. Suddenly, while using TB, all my IMAP folders disappeared from TB, except the inbox. The POP account still works fine. Even the IMAP Sent folder disappeared. All of these folders are active on the server - I can use all of them via web access to the IMAP server. I did not change anything in the account configuration and when I checked it it all looks right. I rebooted my computer and for a few minutes the IMAP folders re-appeared and then disappeared again. I rebooted the computer again and the correct folder tree is visible at first and then it disappears as soon as I try to use that account. I added a new "test" folder to the IMAP account and it stayed there.

When I got to Subscribe under this account, all of the correct folder names show up. I can check each one of the folder names and hit Subscribe, and nothing happens. I have done this many times.

I am running TB version 38.5.1 on Win7x64 pro.

Suggestions please?

I have been using TB successfully for years. I have two email accounts in my TB, one is POP & the other is IMAP. Both have been working fine, including the fact that all folders on my IMAP account have been synchronized and fully useful. Suddenly, while using TB, all my IMAP folders disappeared from TB, except the inbox. The POP account still works fine. Even the IMAP Sent folder disappeared. All of these folders are active on the server - I can use all of them via web access to the IMAP server. I did not change anything in the account configuration and when I checked it it all looks right. I rebooted my computer and for a few minutes the IMAP folders re-appeared and then disappeared again. I rebooted the computer again and the correct folder tree is visible at first and then it disappears as soon as I try to use that account. I added a new "test" folder to the IMAP account and it stayed there. When I got to Subscribe under this account, all of the correct folder names show up. I can check each one of the folder names and hit Subscribe, and nothing happens. I have done this many times. I am running TB version 38.5.1 on Win7x64 pro. Suggestions please?

Vahaolana nofidina

It would appear that Microsoft released a bad update to their office365 / outlook.com servers which broke IMAP folders. Microsoft are working on the issue and promise to remediate the situation. For a workaround, please see my blog post. Unfortunately other an that there is nothing more we can offer until Microsoft fix their servers,

We are tracking this issue in Bug 1241926.

Hamaky an'ity valiny ity @ sehatra 👍 0

All Replies (11)

more options

Is this another with outlook.com?

more options

Not outlook.com but it is an account that is hosted on outlook.office365.com.

Is there a known problem with TB + Microsoft hosting?

This account works fine on my iOS devices. Only TB has the problem.

What's the solution?

more options

At this point we have no solution. We don't understand it really. But the symptoms appear to exactly match those outlook users had with the same site after the November patches were applied.

Are you technical enough to log the connection so we might see where the error occurs?

See https://wiki.mozilla.org/MailNews:Logging

Note Bug 1241926 is being used to manage this issue. So any breaking news will be there first.

more options

The November patches you're referring to - are those in TB, or the Outlook server?

Please keep in mind all of this worked perfectly until yesterday. Something changed yesterday while I was using TB. Could something be corrupted in TB? If so, how can I fix that?

I don't know how to log the connection but if you point me to a description I may be able to do it.

more options

I already pointed you to the description of how to log a connection. I think we are seeing a progression of some patch rolled out in Microsoft's data centre, one server at a time getting the patch and another bunch of folk with folder issues. I really do not think it is Thunderbird at all..

more options

Vahaolana Nofidina

It would appear that Microsoft released a bad update to their office365 / outlook.com servers which broke IMAP folders. Microsoft are working on the issue and promise to remediate the situation. For a workaround, please see my blog post. Unfortunately other an that there is nothing more we can offer until Microsoft fix their servers,

We are tracking this issue in Bug 1241926.

more options

Thank you Matt. This is probably good advice. And I look forward to Microsoft's update.

Note however that this change didn't make any difference with the problem on my system. What did make all the difference, as far as I can tell, was changing the maximum number of server connections to cache to 1 (from 5) in TB - with that change it works fine. This was suggested by my university's IT department, who recognized an incompatibility between TB and the outlook.office365.com server. Perhaps that's a Microsoft problem, I don't know. It's great to have TB working properly again.

FWIW, all this time the same account and server have worked fine on iOS mail.

more options

In your case it might be ios mail that is the root cause. ios mail uses multiple connections as well, but Apple provides no option to limit their use So IOS and OSX devices tend to use all available IMAP connections until the pool on the server is exhausted. Other apps never even get a look-in..

more options

Further update: My problem was resolved for about a day after I (a) unchecked "Show only subscribed folders" and (b) set "Maximum number of server connections to 1" (from 5). However, again today suddenly TB stopped showing any folders other than Inbox and Trash for my IMAP account, while I was using it. I checked those two items above and it had, on its own, changed setting (a) above to be checked, when I had left it unchecked. Unchecking it did not solve the problem. But I closed and restarted TB and now it seems to work, and now both items above are as I had set them. Apparently TB is changing some settings on its own.

more options

If Thunderbird had not completely shut down before you restarted, due to crash, hang or computer restart while running, it is possible for these settings to not persist.

> However, again today suddenly TB stopped showing any folders other than Inbox and Trash for my IMAP account, while I was using it.

This of course is still the outlook problem, combined with the prefs workaround not being in force.

more options

Just had this type of problem this morning, in my case it is an eMail address with @live.de domain that also belongs to outlook.com The eMail folder-structure all of a sudden disappeared, and re-appeared when I clicked the subscribe/refresh button (several times). However interesting --- Thunderbird seemed to have deleted all local contents of the formerly downloaded imap-folders. Thunderbird had to re-download everything all over again. No problem it worked and nothing got lost. But it seems that if something in the folder structure list is broken server side (aparantly it is MS fault) then Thunderbird immediately gets rid of the folder-tree and deletes the local copies of the imap-folder structure. Anyhow, all is well and presumably this is not a thunderbird malfunction.