Inbox delivery troubleshooting checklist

How to troubleshoot emails not arriving to inboxes

Jon Maybury avatar
Written by Jon Maybury
Updated over a week ago

This article is part of a series of pages about avoiding spam filters and troubleshooting inbox delivery.

Are you sending to an internal email address?

If your message is sent to an internal email address please visit the How to troubleshoot internal inbox delivery page

Check the email sending details for the contact that doesn't receive your emails

In order to find bounced email error messages and see details about sends, opens and clicks, check the history of emails sent to a contact in question. A link to the email sending history stats is linked from the contact details page.

On the email sending history page you'll see these details:

Prerequisite: is domain authentication (DKIM) configured?

Setting up sender domain authentication (called DKIM or DomainKeys Identified Mail in technical terms) is a prerequisite to successful inbox delivery. It's a one-time setup that needs to be completed by your IT team. Domain authentication is commonly checked by spam filters and fraud detection software to filter out unwanted emails.

Bounced emails

A bounce means that the message is rejected by the recipient's mail server. A bounce is a known error and it shows up on the email send report. You can review the bounce reason on the "Email sending history page" linked from the contact details page of each contact in your database. Find out more about how email bounces are managed

If there is no bounce

Once the recipient's mail server accepts a message for delivery - there is no bounce recorded - we have no visibility into what decisions that server is making into how to handle it and why.

If there is also no open or click recorded then all we can know for certain is that the email wasn't rejected by the mail server and it wasn't interacted with by the recipient (or in some cases bots) but the email can still be in a spam folder, quarantined or blocked from reaching the inbox or even the spam folder or it can be in inboxes and never opened.

Spam filters are different for each server, which means the same email may pass through one spam filter and be flagged by another. They are also "trained" by individuals so spam filtering within the same provider can vary by user settings.

Note that bounces can take up to 48hrs to show up in reports because in case of transient failures, such as timed out connections, the Envoke mail servers will try to resend the message up to 10 times and only mark it bounced after the resend efforts failed.

To maximize inbox placement you should:

  • ask your contacts to add your sender email (the "from email") to their address book or safe senders list.

  • ask your contacts to check their custom spam filtering rules that may block your email.

  • not send image-only emails. The text to image ratio in your emails should be high: much more text content than images.

  • only send emails to contacts who requested to be emailed and only send content they are subscribed to receive.

  • include personalization in your emails. For example merging contacts' first name in the subject line helps in some cases as spam filters are able to verify that you know something about the person you're emailing (this is often not the case with purchased email lists).

Emails aren't sent in the first place

Contacts who aren't eligible to receive emails are automatically excluded from sends. The only exception to this is when you designate messages as regulatory or mandatory communication.

We don't attempt to send emails to contacts if one of the following applies:

  • Too many bounces over time indicate an invalid email. Learn more about bounce management.

  • The contact is unsubscribed or consent has expired. Learn about consent options.

  • The email i unverified. This applies only if double opt-in is enabled in your account.

When you're about to send an e-blast exclusions due to these reasons are shown on the email delivery estimate page - just before you hit the send button.

The "email sending history" report includes details about all emails sent to a single contact. To access this page, click on the "Email sending history" link from the contact details page. Click the "Detail" link to expand activity details for each email send.

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