Failed to save mailbox : Invalid PID file

One email user lost all of their inbox folder, their sent, archives, junk and trash folders are still there. Using Thunderbird as email program. Trying usermin to check mail i get "Failed to save mailbox : Invalid PID file"



If the contents of the Inbox are missing, it sounds like they may have inadvertently deleted that email.

You can do a quick check if there's any email there though by looking in the "Mailbox" directory of that user's home directory. In there, you should see two directories, "cur" and "new". Each file in those directories represents an email. If they are empty, that means the email has been deleted.

Regarding Usermin and the invalid PID file -- you may want to try restarting Usermin.

You can do that with the command "service usermin restart".

After that, are you able to login?

"cur" folder is 122880 in size and "new" has an email from just 11:40 this morning. But nothing shows up in thunderbird. The mailbox is not empty.

Yeah, your idea of logging in via Usermin, or another email client (such as RoundCube) is a good one. That would rule out an issue with a filter hiding some of the emails that should be in there.

Let us know if it helps when trying another email client.

Also, if you continue to have problems with Usermin even after restarting the service, let us know that too, we can help sort out why that's not working properly.