How to Handle Bounce Mail

When you send an email that does not reach the recipient’s inbox, you might receive an error or bounce-back message. This is called a bounced email, and it is the internet’s way of saying, “Message not delivered”.

What is a bounced email?

A bounced email is an email returned to the sender because it could not be delivered to the recipient. This can happen for several reasons, from technical issues to spam policies.

Why do emails bounce?

Some common causes include:
• Invalid email address – The recipient’s email address is misspelt or no longer exists.
• Mailbox is full – The recipient’s inbox has exceeded its storage limit.
• Server or DNS issues – The recipient’s email server is temporarily down or misconfigured.
• Spam filters – Your email was flagged as spam and rejected.
• Blacklisted IP or domain – Your sending address or IP might be on a blocklist.
• Domain does not exist – The domain part of the email (e.g., @example.com) does not exist or is no longer registered.
• Greylisting – The recipient’s server temporarily rejects emails from new senders to prevent spam.

Are you sending promotional or bulk emails?

If you are sending marketing, promotional, or bulk messages, email providers may treat them differently from regular emails. Such emails are more likely to be:
• Filtered into spam folders
• Rejected due to content or volume
• Blocked if sent too frequently or to too many recipients at once

How are you sending emails?

The method you use to send emails affects delivery.
• Webmail (Titan Mail interface): Generally safe and reliable.
• Third-party clients (e.g., Outlook, Apple Mail, and Thunderbird): Ensure your SMTP settings are correctly configured.
• Contact or registration forms (via your website): These often use SMTP plugins or PHP mail functions. If misconfigured, they can cause delivery problems.
• Bulk mailing plugins or tools: These can trigger bounces if not compliant with sending best practices.

Make sure:
• You use authenticated SMTP settings (with SPF, DKIM, DMARC records).
• You are not overloading the system with high-volume, rapid-fire sends.

Best practices to avoid bounces

• Double-check email addresses before sending.
• Avoid spammy languages, excessive links and images.
• Keep your email list clean and up to date.
• Use verified sending domains with proper DNS records.
• Monitor bounce reports and take action when patterns emerge.
• Avoid sending too many emails in a short time.