Why are my outgoing emails being rejected by the server?

Answered by Tom Adger

There are several reasons why your outgoing emails may be rejected by the server. I will provide a detailed explanation of each possibility.

1. Incorrect email address: One possible reason for email rejection is that you may be entering an incorrect email address. Double-check the email address you are sending to and ensure there are no typos or mistakes. Even a small error can result in the email being rejected.

2. SMTP server authentication disabled: The error message “address rejected” can occur if the SMTP server authentication feature is disabled in your email client. SMTP (Simple Mail Transfer Protocol) is the standard protocol used for sending emails. When you send an email, the server needs to verify your email address and authenticate your email client. If the authentication is disabled, the server cannot verify your email address, resulting in the rejection of your email.

3. IP address blacklisting: If your IP address has been blacklisted by the recipient’s email server, your outgoing emails may be rejected. IP blacklisting occurs when your IP address is flagged for suspicious or malicious activity, such as sending spam emails. In such cases, the recipient’s server may reject your emails as a security measure. To resolve this issue, you can contact your email service provider and request them to remove your IP address from the blacklist.

4. Email size restrictions: Some email servers impose restrictions on the size of attachments or the overall email size. If your email exceeds these limits, it may be rejected by the server. To avoid this, consider compressing large attachments or using file-sharing services to send files instead of attaching them directly to the email.

5. SMTP server configuration: Incorrect SMTP server configuration in your email client can also lead to email rejection. Ensure that the server settings, such as the outgoing mail server (SMTP), port number, and authentication method, are correctly configured. You can consult your email service provider’s documentation or contact their support for the accurate server configuration details.

6. Spam filters: Email servers often employ spam filters to prevent unwanted emails from reaching the recipient’s inbox. If your email triggers certain spam criteria, it may get rejected. Avoid using excessive capital letters, special characters, or suspicious links in your emails. Additionally, make sure your email content is relevant and not overly promotional.

7. Server downtime or maintenance: Sometimes, the recipient’s email server may be experiencing downtime or undergoing maintenance, causing the rejection of incoming emails. In such cases, you can try resending your email at a later time.

To troubleshoot the issue further, you can check the error message or bounce-back email received when your email is rejected. This message may provide specific information about the reason for rejection, allowing you to address the issue accordingly.

It is worth noting that the specific error message or behavior may vary depending on the email client or service you are using. If you continue to experience email rejection issues, it is advisable to contact your email service provider’s support for further assistance.

I hope this comprehensive explanation helps you understand why your outgoing emails may be rejected by the server.