You're using Mozilla Thunderbird and a Hoster using Plesk or your own mail server that uses "Spam" as folder to put Junk into?
Then you might run into a conflict you don't typically see at first glance, at least if you're not using IMAP or not taking a look into subscribed IMAP folders.
Thunderbird uses "Junk" folder, while others use "Spam"
Thunderbird once decided to use "Junk" folder for Spam. Plesk Email Security and possibly other mail filtering tools etc. decided to use "Spam" as default.
In my case for that reason, I entirely switched to "Spam" everywhere and deleted "Junk". It seems to work!
Another example is Dovecot "Spam" folder:
mailbox Spam {
auto = create # autocreate Spam, but don't autosubscribe
special_use = \Junk
}It gets flagged as "Junk" folder. So basically any folder can become the Junk folder - Thunderbird visualizes this by a flame icon.
No "Spam" folder visible in Thunderbird, while subscribed?
This seems to be a bug currently. In "Subscribed folders" of your IMAP account in Thunderbird:
- Uncheck the missing folder
- Save
- Check it again
and in my case, it then appeared!
Hard to switch to a viable default
Now you should make the choice, if to use "Junk" or "Spam" as default folder. This might be personal preferences, but for example, Plesk Email Security doesn't even allow selecting "Junk" (just Spam and Trash) for moving Spam emails. So if one of your tools is limited in such a way, you have your choice.
Afterwards switch all settings, especially the Junk handling in Thunderbird to the resulting folder.
As last step, delete the unwanted Junk / Spam folder. Some days later, you should ensure that it's still gone and not recreated or even filled again.
PS: Often the Webmail application of your Hosting / eMail provider may be helpful to see all folders, manage them and delete the unwanted ones, while eMail applications don't always expose them clearly enough. If I remember correctly, I had similar issues with Outlook in the past...
PS: Mozilla Thunderbird is great! We should help to push things forward by donations!
PPS: If this was helpful for you, I'd be happy about a coffee :)
