Gmail users can now more easily track the source of spam by using a simple trick involving the "+" symbol in their email addresses, according to a recent report. This technique allows users to create unique email aliases for different online services, making it easier to identify which websites are responsible for unwanted messages. For example, someone could use email addresses like prenom.nom+amazon@gmail.com or prenom.nom+leboncoin@gmail.com when signing up for different sites. Gmail's system ignores everything after the "+" and before the "@" symbol, meaning all these variations end up in the same inbox. This feature has been available since 2004 but is still relatively unknown to most users. When spam arrives at an alias like prenom.nom+sitex@gmail.com, the sender's email address is clearly visible, allowing users to pinpoint the source of the spam. This information can then be used to create filters that automatically move similar spam messages to the trash. To test this method, users can send a test email from an external account to the alias, as Gmail hides messages sent from one Gmail account to another to prevent duplicates. These test emails can be found in the "All Messages" section of the Gmail interface or in the Spam folder if Gmail flags the message as suspicious. Some online registration forms may not accept the "+" symbol in the email field, even though it is valid under the standard email format (SMTP, as defined in RFC 5322). In such cases, Gmail provides an alternative method using dots in the email address. For example, p.r.e.n.o.m@gmail.com and prenom@gmail.com both lead to the same account. However, this method is less precise than using the "+" symbol, as it doesn't allow for distinct aliases. This dot trick only works for personal Gmail accounts and not for professional or academic Google Workspace accounts, where dots can be used to distinguish between different email addresses. While this technique doesn't prevent spam from being sent in the first place, it helps users identify which services are responsible for exposing or distributing their email addresses. This information can be used to refine Gmail filters and improve email management, all while keeping all messages in a single inbox.