I have this annoying problem in Gmail. Spammers are by-passing the Gmail spam filters and are so clever that I am not able to create a manual filter of my own to block them. They are sending me junk mails from e-mail IDs of the form:Jewelskart@greatestjewels.in via watchstore.cleanmail.inShoppingkart@shoppers.in via watchstore.cleanmail.inIn general,something@somethingelse.in via watchstore.cleanmail.inNow, I cant set a filter for each and every mail as they are from different IDs. The common part is the via address which is watchstore.cleanmail.in. But when I try creating a filter with watchstore.cleanmail.in in From field, Gmail doesn't list these emails. In short, the filter is not able to detect via addresses.Report Spam/Unsubscribe options aren't working.How can I get rid of these annoying spammers? 
How to block via senders in Gmail
gmail;email;spam prevention
The reason Gmail's built-in filters won't work in this situation is because they can't be applied to the X-Forwarded-For header. That header is where the via domain info is stored. My solution was to use a Google Apps Script to check my inbox every few minutes and automatically filter out messages sent via a specific domain. It actually works really well. Since implementing the script, I haven't had to deal with this type of spam at all. You can read my full walkthrough here: http://www.geektron.com/2014/01/how-to-filter-gmail-using-email-headers-and-stop-via-spam/