Yikes! Are you sure that email was really from DSL? (You can check by opening the email and tapping the sender’s name. I’ve had a lot of emails lately that say they are from DSL, Kohls, Home Depot, etc … but they are not. See my CVS example below.
What can you do? Verify the sender and DO NOT follow any links in the email, even if the sender is legitimate. (Go to their website and navigate from there.)
Second, you can block the bogus email address. After verifying that the address is not legitimate, select Block This Content. Before you start doing this, go into Settings > Mail > Blocked Sender Options and select Send to Trash.
The bad news … you have to do this to each of those crazy emails because the senders keep using different email addresses. But personally, even though it is time consuming, it has eventually reduced the amount of junk email for me. Wish I had better news for you.