Roughly 200 billion emails are sent worldwide every day — that’s an average of 2.5 million messages per second. You press “Send” and your message reaches the other side of the world almost instantly. How does that actually happen?

The journey of an email

Think of an email as a package being shipped. Its first stop is an SMTP server (Simple Mail Transfer Protocol) — it works like your local post office, checking the recipient’s address. The message joins a priority queue until its turn comes up.

The SMTP server identifies the recipient’s domain name — the part after the @ symbol (e.g. in kostas@servicetag.gr, the domain name is servicetag.gr) — and looks up the matching MX server (mail exchange), the server responsible for receiving mail on behalf of that domain.

Why this is worth knowing

When something “gets stuck” with your business’s email, the issue is usually traced to one of these points: incorrect DNS/MX settings, a problem at the hosting provider, or a delay in the queue due to load. Knowing the basic journey helps you describe the problem better to your technician — and understand why restoring email after a move or hosting change can take a little time (typically up to 24-48 hours, while DNS changes propagate worldwide).

Email, a wonderful way to communicate