Every business collects email addresses. From newsletter signups to customer accounts, your email list is supposed to be your most valuable marketing asset. But here's the hidden problem: At least 28% of your email list becomes invalid every single year. People change jobs. They abandon old accounts. They type gmial.com instead of gmail.com . Some give you fake addresses on purpose. If you send a campaign to 10,000 addresses and 3,000 of them bounce, two disasters happen simultaneously: Your money is wasted (you paid to send to dead addresses). Email providers like Gmail mark you as a spammer, and your real customers stop seeing your emails too. An Email Verifier is the quality control checkpoint that prevents this catastrophe. It scans your list before you hit send, identifies which addresses are real and which are dead, and protects your sender reputation. This guide explains exactly how email verification works, why "valid" doesn't always mean "deliverable,...