On rare occasions, stray processes1) can occur and cause odd behavior. On a home machine, problems can sometimes be fixed by rebooting the machine. This is not so practical on a shared server. But you can do the next best thing, i.e., killing all your own processes. From the Linux shell, use the command:
If your PATH is not properly set, you might need to invoke the command by its full pathname, thus:
This command will kill all your processes on the machine on which you are logged in, and will also log you out.
die command will normally do no harm. However, if you were in the middle of doing something, that activity will get aborted and any data that were being written may be lost.
If any new mail was arriving for you, it will not be lost. The mail software is designed to not lose incoming mail even if processes are unexpectedly killed. The mail delivery is simply attempted again.