The common perception is that email messages seem to arrive almost as soon as they are sent. Messages often appear to be delivered “instantaneously.” So, when an email delay occurs, it seems like something must be wrong. Sometimes there is a problem. Sometimes the delay is the result of normal email flow.
If the messages never show up at all, that is a different situation altogether. See “Where’s the Email? The Case of the Missing or Disappearing Email” for diagnosing those issues.
The multi-server delivery path
When an email message is sent, it is given to an email server for processing and delivery. That email server may forward it on to another email server, and so on, until it ultimately arrives in the recipient’s mail box.
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