Sometimes, a recipient's email provider might bounce or reject your email. When this happens, Gmail sends a message that explains why your email was not delivered.
Learn why emails don't reach a recipient
Often, a bounced or rejected email includes an error message. Review the details in the email to understand why your email did not reach your recipient.
Some common reasons include:
- The email address does not exist.
- The recipient's email server is down.
- The email is too large for the recipient's inbox.
- The recipient's inbox is full.
- The recipient's settings do not allow email from you.
- The email is rejected or blocked by the recipient's email provider, which can happen when:
- You send an email to a large group of people.
- Your message is flagged as spam or contains suspicious text or links.
The recipient's email address doesn't exist
Your recipient's email address may not work, or there's a typo in the email address.
What you can do
- Check for these common mistakes in the email address:
- Quotation marks
- Dots at the end of the address
- Spaces before or after an address
- Spelling errors
- Search your contacts for a different address that the same person uses. If possible, ask the recipient for their updated email address.
Your email is flagged as spam or temporarily rejected
If you're sending a message to a large number of recipients, it may get flagged as spam. Your email may also get flagged if you include links or text asking for personal information.
What you can do
- Remove links to websites or text asking for personal information.
- Put all your recipients in a Google Group and send the message to the group instead.
- If you forward email to Gmail, review our mail forwarding best practices.
The recipient's email server couldn't be reached
If Gmail can't connect to the recipient's email server, you get this error.
What you can do
The problem usually goes away quickly without you doing anything. Try sending the email again later.
If you continue to get the error:
- Check if there are any mistakes in the recipient's email address.
- Contact the customer support team of your recipient's email provider.
You've reached the limit for sending email
When you send an email to more than 500 recipients in a single email or more than 500 emails in a day, you get this error.
What you can do
- When you get this error, you should be able to send emails again within 1 to 24 hours.
- If you use your Gmail account through your work, school, or other organization, you have different sending limits.
You get a “HELO/EHLO” error message
When the mail server that responds to Google identifies itself with an invalid value, you get a “HELO/EHLO argument invalid” error message. For example:
501 5.5.4 Empty HELO/EHLO argument not allowed, closing connection.
501 5.5.4 https://support.google.com/mail/?p=helo
501 5.5.4 HELO/EHLO argument “...” invalid, closing connection.
501 5.5.4 https://support.google.com/mail/?p=helo
When mail servers talk to each other, they're required to identify themselves to the receiving server with a HELO or EHLO command. This identification should be the sending machine's fully-qualified IP address or domain name (like mail.example.com). Any other value is considered invalid and can reject your email.
This error usually occurs with devices like printers, scanners, and fax machines that also send mail.
What you can do
- Contact your email provider.
- If you use Gmail for work or school, ask your administrator to send the fully-qualified domain name or IP address of the sending server when they contact Gmail servers.
- For more information about the HELO/EHLO error message, go to RFC 5321, section 4.1.1.1.