Gmail has something called 'Categories', eg: 'Promotions', they are not labels. I'm presuming you have not accessed gmails 'Settings' to see what you are using or allowing. If you look in your webmail gmail account unders 'Settings' and select 'Labels' tab, you will see what gmail allow as imap accessible. This is where you can select what Labels/Folders are used for imap access. They allow 'Labels' as accessible, these are what most people call 'Folders'. re :''Without this... emails is completely unusable. '' Gmail are the ones who provide these Categories for you via webmail. Gmail are the ones who do not allow Categories as accessible via pop or imap. When you choose to move an email out of the standard labels eg: Inbox and into a Category such as 'Social', you are choosing to make all your emails inaccessible by imap or pop. I'm assuming that you did not realise the full extent of what you are choosing to do, but the bottom line is you have selected and I quote to make your ''emails completely unusable'' if you want to use imap or pop. I would suggest you think about the following as an idea. In gmail webmail account. Create 'Labels' that are for eg: 'Social, Promotions and Primary' Then move emails out of eg: Category = Social into Label = Social. Then make Label = Social as accessible via imap. In Thunderbird Subscribe to see Label = Social. All problems solved :) Gmail would prefer to keep you using webmail, but it is up to you whether you choose to use their inaccessible via imap 'Categories' method or create imap accessible Labels to do the same thing. Hope this info helps you understand what has occurred and a possible way of getting around it.