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Discord Also known as: Temporary failure, 4xx error, soft bounce
A deferral is when a receiving email server temporarily refuses a message but suggests trying again later.
A deferral (or temporary failure) happens when an email server cannot accept a message right now but might be able to later. This is different from a hard bounce, which is a permanent rejection. Deferrals typically return a 4xx series error code (like 421 or 451).
Common reasons for deferrals include full mailboxes, server maintenance, rate limiting (sending too fast), or greylisting. Most email service providers (ESPs) will automatically retry sending deferred messages for a set period (usually 72 hours) before giving up and marking it as a bounce.
If you see a spike in deferrals, it often means you are sending too much volume too quickly for a specific provider, or your sender reputation has taken a dip.
A Message Transfer Agent is the server that moves email from one mail system to another. It takes outgoing messages from your email tool and hands them off to the next mail server using SMTP until they reach the right inbox.
Learn more →A triggered email is a message your system sends automatically when someone does something specific, like signing up, leaving items in a cart, or reaching a milestone. It goes to one person based on their action instead of going to your whole list at a fixed time.
Learn more →An automated email that goes out when someone adds items to their cart but leaves without buying. These emails show what they left behind and usually include a direct link back to their cart. Most businesses send a series of 2-3 reminders over a few days, sometimes sweetening the deal with a discount or free shipping offer.
Learn more →Batch email is when you send the same email to many people at once. Your email platform sends it in groups so you can reach a large list without hurting deliverability.
Learn more →Learn more about email bounce rates - what they are, the difference between hard and soft bounces, and how to improve your email bounce rates in the ...
Learn the difference between accepted and delivered email status. Understand email delivery stages, what each status means, and how to track email de...
You emails might be getting blocked for various reasons, so click on the link to find what they are and how prevent this from happening again.