You may see the following error messages and codes when using Gmail with Google Workspace . The messages and codes are helpful tools for diagnosing and troubleshooting email problems.
Gmail appends one or both of the following identifiers to all error messages to show you the source of the error:
- gsmtp (Google SMTP) is added to all errors.
- gcdp (Google Custom Domain Policies) is added to errors resulting from customized rules created by the administrator.
For example, "550 5.7.1 This message violates example.com email policy. - gcdp <sessionid> - gsmtp" indicates that the error is a result of a custom rule created by the administrator.
For more information, visit About SMTP error messages.
Note: Error #2014 is related to a Chrome browser extension. Disable your Chrome extensions one at a time to determine which extension is causing the error. The full text of error #2014 is: Oops... the system is experiencing a problem (#2014) - Try again.
SMTP error messages
| 421, "4.3.0", Temporary System Problem. Try again later |
| 421, "4.4.5", Server busy, try again later. |
| 421, "4.7.0", IP not in whitelist for RCPT domain, closing connection. |
| 421, "4.7.0", Our system has detected an unusual rate of unsolicited mail originating from your IP address. To protect our users from spam, mail sent from your IP address has been temporarily blocked. For more information, visit Prevent mail to Gmail users from being blocked or sent to spam. |
| 421, "4.7.0", Temporary System Problem. Try again later. |
| 421, "4.7.0", TLS required for RCPT domain, closing connection. |
| 421, "4.7.0", Try again later, closing connection. This usually indicates a Denial of Service (DoS) for the SMTP relay at the HELO stage. |
| 450, "4.2.1" The user you are trying to contact is receiving mail too quickly. Please resend your message at a later time. If the user is able to receive mail at that time, your message will be delivered. For more information, visit Limits for sending & getting mail. |
| 450, "4.2.1", The user you are trying to contact is receiving mail at a rate that prevents additional messages from being delivered. Please resend your message at a later time. If the user is able to receive mail at that time, your message will be delivered. For more information, visit Limits for sending & getting mail. |
| 450, "4.2.1", Peak SMTP relay limit exceeded for customer. This is a temporary error. For more information on SMTP relay limits, please contact your administrator or visit SMTP relay service error messages. |
| 451, "4.3.0", Mail server temporarily rejected message. |
| 451, "4.3.0", Multiple destination domains per transaction is unsupported. Please try again. |
| 451, "4.4.2", Timeout - closing connection. |
| 451, "4.5.0", SMTP protocol violation, visit RFC 2821. |
| 452, "4.2.2", The email account that you tried to reach is over quota. Please direct the recipient to Clear Google Drive space & increase storage. |
|
452, "4.5.3", Domain policy size per transaction exceeded, please try this recipient in a separate transaction. |
| 452, "4.5.3", Your message has too many recipients. For more information regarding Google's sending limits, visit Limits for sending & getting mail. |
| 454, "4.5.0", SMTP protocol violation, no commands allowed to pipeline after STARTTLS, visit RFC 3207. |
| 454, "4.7.0", Cannot authenticate due to temporary system problem. Try again later. |
| 454, "5.5.1", STARTTLS may not be repeated. |
| 501, "5.5.2", Cannot Decode response. |
| 501, "5.5.4", HELO/EHLO argument is invalid. For more information, visit HELO/EHLO email error. |
| 502, "5.5.1", Too many unrecognized commands, goodbye. |
| 502, "5.5.1", Unimplemented command. |
| 502, "5.5.1", Unrecognized command. |
| 503, "5.5.1", "EHLO/HELO first. |
| 503, "5.5.1", MAIL first. |
| 503, "5.5.1", RCPT first. |
| 503, "5.7.0", No identity changes permitted. |
| 504, "5.7.4", Unrecognized Authentication Type. |
| 530, "5.5.1", Authentication Required. For more information, visit Can't sign in to your Google Account. |
| 530, "5.7.0", Must issue a STARTTLS command first. |
| 535, "5.5.4", Optional Argument not permitted for that AUTH mode. |
| 535, "5.7.1", Application-specific password required. For more information, visit Sign in using App Passwords. |
| 535, "5.7.1", Please log in with your web browser and then try again. For more information, visit Check Gmail through other email platforms. |
| 535, "5.7.1", Username and Password not accepted. For more information, visit Can't sign in to your Google Account. |
| 550, "5.1.1", The email account that you tried to reach does not exist. Please try double-checking the recipient's email address for typos or unnecessary spaces. For more information, visit Fix bounced or rejected emails. |
| 550, "5.2.1", The email account that you tried to reach is disabled. |
| 550, "5.2.1", The user you are trying to contact is receiving mail at a rate that prevents additional messages from being delivered. For more information, visit Limits for sending & getting mail. |
| 550, "5.4.5", Daily sending quota exceeded. For more information, visit Email sending limits. |
| 550, "5.4.5", Daily SMTP relay limit exceeded for user. For more information on SMTP relay sending limits please contact your administrator or visit SMTP relay service error messages. |
| 550, "5.7.0", Mail relay denied. |
| 550, "5.7.0", Mail Sending denied. This error occurs if the sender account is disabled or not registered within your Google Workspace domain. |
| 550, "5.7.1", Email quota exceeded. |
| 550, "5.7.1", Invalid credentials for relay. |
| 550, "5.7.1", Our system has detected an unusual rate of unsolicited mail originating from your IP address. To protect our users from spam, mail sent from your IP address has been blocked. Review Prevent mail to Gmail users from being blocked or sent to spam. |
| 550, "5.7.1", Our system has detected that this message is likely unsolicited mail. To reduce the amount of spam sent to Gmail, this message has been blocked. For more information, visit Why has Gmail blocked my messages? |
| 550, "5.7.1", The IP you're using to send mail is not authorized to send email directly to our servers. Please use the SMTP relay at your service provider instead. For more information, visit 'The IP you're using to send email is not authorized...'. |
| 550, "5.7.1", The user or domain that you are sending to (or from) has a policy that prohibited the mail that you sent. Please contact your domain administrator for further details. For more information, visit Sorry, a policy is in place that prevents your message from being sent. |
| 550, "5.7.1", Unauthenticated email is not accepted from this domain. |
| 550, "5.7.1", Daily SMTP relay limit exceeded for customer. For more information on SMTP relay sending limits please contact your administrator or visit SMTP relay service error messages. |
| 550, "5.7.26", " Unauthenticated email from domain-name is not accepted due to domain's DMARC policy. Please contact the administrator of domain-name domain. If this was a legitimate mail please visit Control unauthenticated mail from your domain to learn about the DMARC initiative. If the messages are valid and aren't spam, contact the administrator of the receiving mail server to determine why your outgoing messages don't pass authentication checks. |
|
550, "5.7.26", "This message does not have authentication information or fails to pass authentication checks (SPF or DKIM). To best protect our users from spam, the message has been blocked. Please visit Prevent mail to Gmail users from being blocked or sent to spam for more information." |
| 550, "5.7.26", "This message fails to pass SPF checks for an SPF record with a hard fail policy (-all). To best protect our users from spam and phishing, the message has been blocked. Please visit Prevent mail to Gmail users from being blocked or sent to spam for more information." |
| 552, "5.2.2", The email account that you tried to reach is over quota. |
| 552, "5.2.3", Your message exceeded Google's message size limits. For more information, visit Send attachments with your Gmail message. |
| 553, "5.1.2", We weren't able to find the recipient domain. Please check for any spelling errors, and make sure you didn't enter any spaces, periods, or other punctuation after the recipient's email address. |
| 554, "5.6.0", Mail message is malformed. Not accepted. |
| 554, "5.6.0", Message exceeded 50 hops, this may indicate a mail loop. |
| 554, "5.7.0", Too Many Unauthenticated commands. |
| 555, "5.5.2", Syntax error. |
