Glossary

Queued email

Queued email

queued email is a message that’s temporarily held before being delivered. Email queuing can happen for two main reasons: 

  1. Intentional queuing by the sender

Senders may queue emails deliberately to:

  •  Throttle message volume and avoid overwhelming their infrastructure  
  • Align with send-time optimization strategies based on user behavior  
  • Pace delivery for IP warming or rate-limited providers like Gmail or Yahoo -Coordinate campaigns across time zones
  1. Automatic queuing by mail servers  

Messages may be queued automatically if:

  • The receiving server is busy, unavailable, or temporarily deferring messages  
  • Sending limits (throttling) are enforced by the ESP or infrastructure  
  • A backlog is building due to high volume or retries after soft bounces  

Queued email is not failed emailit’s just waiting its turn.  

At Mailgun, queued statuses often show up in logs as queued or delayed, and most retry automatically unless they hard fail after a timeout window. 

Create beautiful, responsive emails in minutes.

Email made easy.