Just a few days ago, Shoemoney shared an interesting tip.
By simply adding "+whatever" to your email address whenever you opt into a list will help to track your email address.
For example, say your email is email@example.com and you want to opt into ShoeMoney System.
You add a "+shoemoneysystem" behind your email username.
Like this, firstname.lastname@example.org.
Most email systems will let you use the + symbol as a separator and you can add whatever after that to track that email.
Everything after the + symbol will be ignored by gmail and most email providers, so email still goes to email@example.com.
Now this makes it very easy to track your email.
If you received an email with the "+whatever" different from the sender, this is a good indication on who has been "abusing" your email address.