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Even small formatting errors in an email address can prevent delivery entirely. Mail servers validate the address structure before attempting delivery.
The SMTP Error 553 – Invalid Email Address Format indicates that the email address does not follow valid formatting rules. The server cannot route messages to incorrectly structured addresses. This error is detected before any delivery attempt occurs.
TABLE OF CONTENTS
Common Causes of SMTP Error 553
Email addresses are often rejected due to simple but easily overlooked issues. These problems usually occur at the point of entry rather than during transmission.
They include:
- Typographical errors, such as missing letters or misplaced punctuation.
- Using commas or semicolons instead of full stops in the domain name.
- Incorrectly entering multiple email addresses into a single address field.
- Automatically filled addresses that include hidden spaces or line breaks.
- Invalid top-level domains, such as .con instead of .com.
- Manually edited mailing lists that were not revalidated afterwards.
How to Resolve the Error 553
1. Carefully review the email address for missing or incorrect characters.
2. Ensure the address includes a valid “@” symbol and domain name.
3. Remove any spaces or unsupported special characters.
4. Confirm that the domain exists and is active.
Additional Information
- SMTP Error 553 indicates that the email address structure is invalid.
- Mail servers validate address syntax before attempting delivery.
- Formatting errors can occur due to extra spaces or invalid characters.
- Copy-pasting addresses increases the risk of hidden formatting issues.
- Bulk mailing systems commonly encounter this error when lists are not validated.
- Address validation tools help prevent repeated formatting errors.
- Ensuring correct address syntax improves delivery success rates.
Login to Hosted.com® Account
1. Go to the Hosted.com® website Account Login page.
2. Enter your Email and Password and click the Sign In button.
3. You will see the Hosted.com® Dashboard, displaying the Manage Account menu on the left and your Account Information, Account Overview and Open Support Tickets on the right.
Login to cPanel from your Hosted.com® Dashboard
4. Click on Manage Services to view the sub-dropdown menu and select the hosting package for the domain you want to work with – in our example we are using WordPress Hosting.
5. Click the Manage button to the right of the domain name you want to access.
6. The display will now show Product Information, Quick Manage, Resource Usage and Site Statistics for that domain name.
7. Under Product Information, scroll down to Control Panel, which will display cPanel to the right, and click on the Login button.
8. The cPanel Dashboard will now be displayed.
