Posted 06 September 2015 - 09:45 AM
You can do as suggested by Nikhil_CV and simply click the unsubscribe link.
If the sites are legitimate they will (or should) unsubscribe your email.
At this point I will say that if you get spam mail and there is an unsubscribe link, do NOT use it. These types of mail often use that tactic to confirm that your email address is still valid. The result is even more spam.
Now I will answer your question "Is there a quick settings in Gmail, which enables me block those emails with just a few clicks?"
Yes, there is.
Sign in to Gmail.
While looking at your Inbox, place a checkmark in the box to the left the mail you want to filter.
Click the drop-down arrow next to MORE.
Choose Filter messages like these.
By default, the sender address is already filled in the From field. Use this for mails from the same address.
You will not need to fill out the Subject field UNLESS subject is always the same but the sender varies.
Click Create filter with this search.
The next screen will allow you to choose what to do with the mail.
I saw no option to send the mail to a specific folder such as Trash or Junk. The only option which makes sense is DELETE, which means it will be deleted from the server and you will never see it.
After you choose what to do with it, click CREATE FILTER.
If you have more than one mail by that sender in you inbox, check the box next to "Also apply filter to (a number will be here) matching conversation" BEFORE creating the filter. Doing this first will automatically apply the rule to the existing mails still in the Inbox.