Email's subjects are labelled as **SPAM**

Part of my incoming emails are labelled as **SPAM** (even though they are not SPAM). They are not being moved to Junkbox, instead their subjects are changed to “**SPAM** …” How can I disable this function?

Depending on your email service (Gmail Yahoo etc)  you may need to use your browser to login to that account and tell the email service that it is not spam.   Also one can right click the email in emclient and select move to inbox and remove from blacklist if it is in the junk or spam folder.    If it only appears in the inbox  and not in the junk or spam folder that I believe it is being marked as spam by your email service  and not by emclient. 
Hope this helps.