1. Dot Invariance (RFC & Gmail)
Gmail does not recognize periods as characters in usernames. Adding or removing dots from a Gmail address does not change the destination: john.smith@gmail.com and j.o.h.n.s.m.i.t.h@gmail.com belong to the exact same mailbox.
2. Plus Sub-Addressing (RFC 5233)
Adding a plus sign (+) followed by any word or number creates an active virtual address without modifying your account. If spam starts arriving at yourname+store@gmail.com, you know precisely who leaked or sold your email.
3. Automated Mail Sorting
Using the exported mailFilters.xml, you can program Gmail to automatically bypass the inbox, assign custom labels, mark as read, or forward incoming mail based on the specific alias the sender contacted.