Delete Gmail Spam In Mail


Searched for this on the forum and at google, found some old threads that kind of touch my problem, but not really.

I have a mid 2011 MacBook Pro with 4 gigs and Yosemite with an SSD. OK - I'll get some more RAM one day.

I use Mail with imap for several mail accounts and keep the inboxes pretty clean - messages out of sight and out of mind. I can't seem to get the Junk mailbox to cooperate with the same practice. I would look through the messages to make sure nothing was there by mistake, then I would select all and trash them - using just delete and later trying command delete. They would obediently disappear but the next time I would open Junk, the messages were all there again.

Short version of the story is there is one message in the junk box that keeps all the others from deleting. I know this because if I select everything but this one, they do get trashed.

The offending post has been with me since 2012 and is from "CorporateOffices at gmail etc" and has a "dot" in the subject line and the legend "This message has no content". The body of the mail has a shoddy graphic of a pair of Xbox games. Needless to say I haven't ever clicked on the pic.

I went to gmail directly to try to delete it there, but because there is no "Junk" folder I could not find the post. I searched for the sender without success. I searched for . in the subject line - the offending post still does not appear.

I would like to clean myself of this intrusion, does anyone know how? Is it lodged in the imap system at gmail or is it in the labyrinth that is the folder system of mail?
Have you set the mailbox behaviour to automatically delete all junk mail from the gmail server after one day/week/month?

The option is in Mail/Preferences/Accounts/Mailbox Behaviours. Then select the gmail account in the sidebar.

Or try removing from Junk and using the "Advanced" tab and remove all the incoming mail from the server "Now". But only do that if the mail you want is on your computer and not pulled from the server each time.