Time for which email covered the distance from sender to recipient.
When the letter is created, the sender says creation date. When a letter comes to us, we look at the clock and know how much time the letter was on the way.
The reason that this number may be inaccurate:
- The sender pointed incorrect date
- The sender misconfigured clock
- The clock is not synchronized with world time
Causes when the letter is in the way for a long time:
- Sender SMTP Server is busy
- Email queued scheduling of tasks
- Network or server error
- Sender sent the email with a delay
- Email with advertising or spam usually is sent postponed