Email Analytics: Email Statuses and What They Mean

When you send an email to your subscribers via SendGrid (Certain's 3rd Party Email Provider), only a few things can happen to that message between SendGrid and the email recipient's server. Those events are:

• Delivered — the recipient's server accepted the message
• Bounce — the recipient's server denied the message, and the address the message is sent to is suppressed by SendGrid moving forward
• Blocked — the recipient's server denied the message, and the address is not suppressed by SendGrid moving forward
• Deferred — the recipient's server delayed acceptance of the message

Delivered

A common misconception is that a delivered message is a message that made it to the inbox. A message registered as delivered has been accepted by the receiving server from SendGrid. The receiving server still has to decide what to do with that message.

The receiving server can deliver the message to the intended inbox. The receiving server can also send the message to the spam or junk folder. Less frequently, the receiving server might choose to drop that message. Dropping a message means the message will not be findable to the recipient, even if the recipient looks for the message in the spam folder. Dropping a message is rare.

The decision about where to put the message comes down to the sender's sending reputation and the content being sent. Senders who generate excessive spam complaints from recipients are more likely to see their emails not make the inbox. Senders sending content known by inbox providers to generate high rates of spam complaints are more likely to see their emails not make the inbox. A high percentage of delivered emails is great. Simply getting emails delivered is only part of email success.

Bounce

Some people in the industry use terms like “hard bounce” and “soft bounce” to describe messages that were refused by the receiving server. SendGrid's terminology separates returned messages into bounces and blocks.

The code indicates that the reason for the refusal is a permanent issue with that server or recipient address.

The most common reason an address will bounce is that the address in question is not valid.

Blocked

Blocked emails are similar to what some people refer to as a “soft bounce.” Blocked emails are ones where the receiving server returned a reason for refusal. The reason indicates a non-permanent rejection for that address. Blocked means a rejection of that message. Blocked does not indicate the quality of the address being sent to.

Common reasons a message might be blocked include a sending IP or domain that has been list denied. Common reasons a message might be blocked include campaign content elements the inbox provider deems “spammy.” Common reasons a message might be blocked include a technical issue between the two servers at the time the campaign was attempted.

Deferrals

A deferred event, or deferral, is an event SendGrid receives back from the receiving server. A deferral tells SendGrid that the receiving server has temporarily limited access to its system. A deferral can be thought of as a busy signal.

A deferral does not mean that a message will not be delivered. A deferral signals that a message will not be delivered immediately.

A message might be deferred at an inbox provider because the inbox provider is seeing too many spam complaints for an email that has already been delivered. A message might be deferred at an inbox provider because the receiving server is having technical issues at that time.

When SendGrid sees mail being deferred at a particular inbox provider, SendGrid continues to try to deliver the message. SendGrid continues to try to deliver that message for up to 72 hours. If a message to a recipient is deferred for more than 72 hours, the deferral turns into a block. If the message is not deferred for more than 72 hours, the deferral results in a delivery event once the receiving server has accepted the message.

Keeping an eye on these events can give more insight into what is happening with emails as the emails journey from the Certain Platform to SendGrid to the recipient’s inbox. If you want to dive deeper into email delivery health, check out SendGrid's Email Deliverability Guide.