Email delivery failure : the reasons and it's solutions

Why did Email Delivery fail?

Whenever an email campaign is sent, the worst-case scenario is that your emails do not reach the recipient’s inboxes. If your emails are not delivered, they have bounced, indicating a type of email delivery failure. Emails can bounce for various reasons, two types: Hardbounce and softbounce. Understand the difference between Soft Bounce and Hard Bounce.

What is Email Hardbounce?

A hard bounce occurs when the recipient’s mail server permanently rejects an email and cannot deliver it successfully. Common reasons for hard bounces include invalid email addresses, non-existent recipient mailboxes, and blocked email addresses.

What is Email soft bounce?

A soft bounce is a temporary email delivery failure that happens when an email cannot reach the recipient’s mailbox, but the issue may resolved after a short period. Common reasons for soft bounces include full mailboxes, temporary server issues, exceeded message size limits, and recipient email server overload.

Why your Emails aren’t reaching the Inbox:

Greylisting:

Some email servers utilize greylisting as a spam prevention technique. When you send an email, the receiving server temporarily rejects it, asking the sending server to retry later. Legitimate servers will retry, while many spam-sending servers will not. If your server doesn’t retry after a delay, your email won’t reach the inbox.
Blocklisted Sender Domain or IP:

If email providers have flagged your sender domain or IP address for spamming or other malicious activities, they may block or filter your emails, preventing them from reaching the inbox.
Server or Network Issues:

If you see the message email delivery is temporarily disabled, then there is a technical problem with your email server or network infrastructure. Recipients’ inboxes may not receive emails on time if they are delayed, lost, or rejected during the delivery process.
Internet Connectivity Issues:

If disruptions occur in your internet connection or your email server’s connectivity, it can affect the delivery of your emails to the intended recipients, leading to a message that email delivery is temporarily disabled.
Bounced or Rejected Emails:

If the recipient’s email server rejects your email due to a full inbox, invalid recipient address, or strict spam filtering rules, your email will not reach the intended recipient.
Email Account Issues:

If email providers have flagged your sender domain or IP address for spamming or other malicious activities, they may block or filter your emails. This action prevents them from reaching the inbox.
Domain Name Issues:

Problems such as an expired registration, setup errors, or your domain being marked as suspicious can cause issues with sending emails.
Invalid or Non-Existent Email Address:

Sending emails to invalid or non-existent addresses will result in email delivery failures. The email servers will not be able to route the messages to the intended recipients.
Sender Authentication Issues:

Email authentication protocols like SPF, DKIM, and DMARC help ISPs verify that emails are legitimately sent from your domain. If you misconfigure these settings or they are missing, your emails might be flagged as suspicious or fraudulent, landing them in spam folders or leading to outright rejection..
Spam Filters:

ISPs use sophisticated spam filters that analyze various factors like email content, sender reputation, and user engagement to determine whether an email should be delivered to the inbox or filtered as spam. If your emails trigger these filters due to suspicious content, poor sender reputation, or other reasons, they may not reach recipients’ inboxes.
Complaint Rate:

High recipient complaints, such as marking your emails as spam or unsubscribing in large numbers, signal to ISPs that your emails are unwanted. This can negatively impact your sender’s reputation and cause ISPs to divert your emails away from the inbox.

How to fix email delivery failure:

Fixing email delivery failures depends on identifying the specific cause of the failure. Here’s a general guide on how to find email delivery failures:
- Identify the Reason for Failure:
  
  Review any error messages or bounce-back notifications to understand why the email delivery failed. Common reasons include wrong recipient addresses, blocklisting, login problems, content blocks, server issues, and problems with the recipient’s mailbox.
- Optimize Email Content:
  
  Check the email content for things that might make spam filters block your emails. Avoid using spammy language, excessive punctuation, or misleading subject lines.
- Resend the Email:
  
  After fixing any issues you find during troubleshooting, resend the email to the recipient.
- Follow up with Recipient:
  
  If you can’t fix the email delivery failure or it keeps happening, try contacting the recipient through another way to make sure they get the message.
- Review Authentication Settings:
  
  Ensure that your SPF, DKIM, and DMARC records are correctly configured in your DNS settings to authenticate your emails. Update or correct any misconfigurations.
- Monitor Server and Network Status:
  
  Check the status of your email server for any reported outages or maintenance. Monitor network performance and troubleshoot any connectivity issues with your email server or SMTP provider.
Follow these steps and address the specific cause of the email delivery failure to improve your chances of successfully delivering emails to recipients’ inboxes.