This article explains how email delivery works at the server level and how that affects your deliverability.

When you send a mailing from your Emma account, the response tracking that begins is actually happening at two distinct levels: the server where your recipient's inbox is hosted and managed and the inbox itself. On the Response page, you can view automated mailings, in progress mailings, test mailings, and sent mailings. To access this, simply navigate to your Response tab and click on the name of a campaign to open it.

In this article Information that receiving servers send to Emma Emails sent Emails delivered Bounced emails Soft bounces Hard bounces Error code links by company Additional resources

Information that receiving servers send to Emma

The metrics for emails sent, received, in progress, and bounced are all tracked at the server level when we receive certain codes (and messages to go with them) back from the receiving servers. Beyond that initial level of tracking, the receiving servers control much of what happens from there. They decide whether to deliver emails immediately to recipients or to run them through a filtering program of some sort. And, like any server network, they occasionally experience problems like too much traffic, viruses, or overflowing inboxes.

The information that Emma gets sent from receiving servers is how we generate the delivery and bounce data on your mailing response pages.

Emails sent

Quite literally, this is the number of emails that Emma attempted to send on your behalf. For example: If you selected a group of 1,000 people to send your mailing to, then your sent total should eventually be 1,000.

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Emma will only attempt to reach the Active members of you audience, not members in Error or Opt-out status. Additionally, your totals for sent, received, and bounced mailings may take up to 30 hours to fully tabulate, as Emma continues trying to reach each email address over a period of hours, if the first several attempts fail.

Emails delivered

Emails delivered is the number of emails that were successfully delivered to servers on the other end. When an email is delivered, the server that receives it usually sends Emma a response code. The codes tell Emma whether the email was successfully accepted, rejected because of a network or inbox problem, or bounced back because the email was deemed unfamiliar or unwanted. There is a standard set of response codes and most servers are good about using those codes in the right way. At that point, we're relying on the server to finish the delivery job and pass the email on to its intended recipient.

Ⓘ	Once a mailing is accepted by the receiving server, Emma can no longer "see" it. As a result, it's entirely possible for an email to be received by the server but never reach a recipient's inbox.

Bounced emails

Before an email can reach someone's inbox, it has to be accepted by the host server. So, a bounced status represents emails that were kicked back as undeliverable by the receiving server. Bounces occur when the SMTP transaction between our mail server and your recipient’s mail server fails. The error codes given at the time of the bounce might be standardized at each organization, but they can be quite different from provider to provider.

There are two main categories for bounces: soft bounces and hard bounces.

Soft bounces

A soft bounce is a temporary failure due to an outage, full mailbox, or another issue that should resolve itself. They are typically represented by a three digit bounce code starting with a 4. Soft bounces are considered temporary, so delivery is reattempted over a 30-hour period before giving up on reaching the receiving server. Any email addresses still bouncing after four attempts will be marked as a soft bounce, and your campaign's delivery will be complete. Additionally, any address that soft bounces will remain an Active contact in your audience unless it soft bounces three consecutive times, at which point it will be moved to Error status and not included in future sends.

Hard bounces

A hard bounce represents a permanent obstruction to email delivery, such as a nonexistent email address, a block due to content, or the server is rejecting your email as junk mail or spam. They are typically represented by a three digit bounce code starting with a 5. Hard bounces are deemed invalid and moved to Error status. These email addresses won't be sent to again unless you re-activate them.

If you feel an email address is inaccurately displayed as an Error, or notice a delivery problem with an inbox provider, please reach out to our Support team before reactivating that address or taking action to resolve a delivery problem. Our team will gladly investigate the Error status of any recipient or group and help restore addresses for you, and will work directly with inbox providers and blocklists to resolve your sending issues. You can contact our Support team by clicking on the Get Support icon in the bottom right corner of this page, which will access our virtual assistant.

Error code links by company

For reference, we've compiled a list of error code help documentation by ISP / company. Please note that we don't manage or monitor these sites, but they can be helpful if you're trying to track down the reason for a bounce.

• Cox
• Gmail
• Microsoft
• Mimecast
• Yahoo

Additional_resources

• Response tab: Overview
• Mailing response data: Overview
• Mailing response data: Opens, clicks, and more
• Mailing response data: Exports
• Mailing response data: 24-hour response summary email
• Why does my email have so many clicks?
• Clicks, links, and tracking: Frequently asked questions