Mail server Trouble Shooting

    Important Note:

    Please ensure that the following checks are completed and then reach out to our support team with the results for further assistance: 

    • Check your connectivity to the Mail Server using Telnet. For example: telnet smtp.gmail.com 587
    • If the mail server ports are blocked on your server by a Firewall, unblock the ports to allow TCP Connections.
    • If the mail server ports are blocked on your server by an Antivirus, remove Network Configuration Manager folder from the antivirus scan.
    • Ensure that the authentication provided to access the Mail Server is appropriate.
    • The Username provided for authentication should have the authorization to send as the designated From Email ID.
    • Make sure that your mail server allows you to send emails to all IP addresses, even if they are emails belonging to external networks.
    • It is recommended to use a trusted IP address/proper authentication so that the SMTP server does not block the relaying process.
    • Make sure there is sufficient memory in the mail server drive/mail box to receive mails.

Types of Issues:

1. Connection Issues :

Unable to connect to the SMTP Server

Error Code :

  • Could not connect to SMTP host: xxxx, port: yyyy , response: -1

  • Unrecognized SSL message, plaintext connection?

  • Could not convert socket to TLS;

Cause :

  • Unable to connect to the specified port with the secured connection details provided.

Possible workarounds :

  • Disable SSL under Secure Connection Details in case of unrecognized SSL message.
  • Recheck the Secure connection details.
  • Specify the port with respect to the secure connection mode.
  • Manual configuration errors are
    • Port : port of SSL connection, Secure Connection : None/TLS - Timeout error occurred while establishing socket connection
    • Port : port of TLS connection, Secure Connection : None/SSL - Unable to connect Mail Server without TLS connection
    • Port : port of plain connection, Secure Connection : SSL - Unrecognized SSL message, plaintext connection?

Timeout error occurred while establishing socket connection

Error Code :

  • javax.mail.MessagingException: Exception reading response

  • java.net.SocketTimeoutException: Read timed out

Cause :

  • Unable to reach the mail server resulting in timeout. This is most probably a connection issue.
  • Unable to connect to the specified port with the secured connection details provided.

Possible workarounds :

  • Specify the port with respect to the secure connection mode.
  • Recheck if the ports are blocked on your server by a firewall. Unblock the mail server port to allow TCP Connections
  • Telnet the Mail Server to verify connectivity, For example telnet smtp.gmail.com 587
  • Increase timeout to a maximum of 300seconds.
  • To take assistance from our support team, contact ncm-support@manageengine.com with your Mail Server Settings screenshot, Error Message and Telnet result.

Unable to connect Mail Server without TLS connection

Error Code :

  • 530 5.7.0 Must issue a STARTTLS command first

  • javax.mail.MessagingException: Could not convert socket to TLS;

Cause :

  • TLS secured connection is required

Possible workarounds :

  • Enable TLS under secure connection details
  • Recheck if the specified port is set to the TLS connection.
  • Recheck the authentication details.

SSLHandshakeException

Error Code :

  • javax.net.ssl.SSLHandshakeException cannot be cast to javax .mail.MessagingException

Cause :

  • Handshake Failure is caused when Network Configuration Manager server and Mail server are unable to communicate successfully.
  • Incorrect Port and/or incorrect Secure connection details.

Possible workarounds :

  • If your build is 12200 and below, upgrade it to the latest version to make your mail server work without issues.
  • Recheck the Port and the Secure connection details.
  • If SSL is enabled, Import mail server's certificate into Network Configuration Manager's Certificate/TrustStore File option available under Settings>> SecuritySettings tab.

2. Authentication Issues :

Authentication unsuccessful, even after providing correct username and password

Error Code :

  • 535 5.7.139 the user credentials were incorrect

  • 535 5.7.139 Authentication unsuccessful, as the request did not meet the criteria to be authenticated successfully. Contact your administrator.

  • 535 5.7.139 Authentication unsuccessful, SmtpClientAuthentication is disabled for the Tenant. Visit https://aka.ms/smtp_auth_disabled for more information.

Cause :

  • If Basic Authentication was being used.
  • If SMTP Authentication has been disabled in your mail server.

Possible workarounds :

  • Switch to a more secure, Modern authentication(OAuth 2.0) in your mail server
  • Enable SMTP Authentication in your mail server

Click here to see the steps to fix the 535 5.7.139 error.

Mail server authentication failed

Error Code :

  • 535 5.7.8 Error: authentication failed

  • 535 5.7.3 Authentication unsuccessful

Cause :

  • Username and/or password is incorrect.
  • Unable to authenticate Mail server resulting in a timeout.
  • Unable to reach the mail server resulting in timeout.

Possible workarounds :

  • Check the proper syntax of the Username that is entered in the mail server.
  • Provide the Username that authenticates the given From Mail ID
  • Office365 requires the Username in your SMTP configuration to be your full email address and it should be in the following format: your_username@yourOffice365domain.com
  • Increase the timeout to a maximum of 300seconds
  • Mail server with OAuth2/XOAUTH2 login mechanism requires OAuth access token instead of passwords.

Application-specific password required

Error Code :

  • 535-5.7.8 Username and Password not accepted.

Cause :

  • The Gmail account doesn't have access from an external application

Possible workarounds :

Username and Password not accepted

Error Code :

  • 534-5.7.9 Application-specific password required

Cause :

  • The Gmail account has been enabled with Two-step verification for authentication.

Possible workarounds :

From Email account not authenticated to send anonymous mails

Error Code :

  • 530 5.7.57 SMTP; Client was not authenticated to send anonymous mail during MAIL FROM [<MailServer>]

Cause :

  • Mail server may require authentication for given From Email ID.
  • Mail server may require TLS connection.

Possible workarounds :

  • Ensure if the given From Email ID requires authentication to send mails and provide the same under Authentication details.
  • Enable TLS connection and give respective port.

3. Permission Issues :

Unable to send email

Error Code :

  • com.sun.mail.smtp.SMTPAddressFailedException: 550 5.7.1 Unable to relay

  • com.sun.mail.smtp.SMTPAddressFailedException: 554 5.7.1 : Relay access denied

  • com.sun.mail.smtp.SMTPAddressFailedException: 554 5.7.1 : Client host rejected: Access denied

Cause :

  • Invalid email address.
  • Mail server may require authentication.
  • Permission issue while the Network Configuration Manager server is trying to connect to the Mail server for sending mails.
  • Mail Server may not be able to send emails to the external domains.
  • Port number configured wrongly for the secure connection selected.

Possible workarounds :

  • Recheck the From and To mail address used.
  • Check if mail server requires authentication. If yes, provide the Username and password
  • Give access to Network Configuration Manager's server and IP/Hostname in the mail server.
  • Add server IP to the relay exception list so it is reachable and not labelled as antispam.
  • Configure proper secure connection details (Choose None if TLS/SSL connection is not enabled in the mail server)
  • Choose between TLS/ SSL/none with respect to port or vice versa. Some times there may be different connections enabled for different ports for the same mail server [ eg : server name : smtp TLS will be enabled for 587, SSL may be enabled for 465, none for 25]
  • Contact the mail admin with the respective error code to check if the mail address is able to send emails to an external domain.

 

Unable to send email to a different domain

Error Code :

  • com.sun.mail.smtp.SMTPAddressFailedException: 550 5.7.54 SMTP; Unable to relay recipient in non-accepted domain

Cause :

  • Open external relay (sending of emails from a valid internal address to an external recipient) may be restricted
  • There might be a restriction in the mail server to prevent emails being sent by unauthenticated users to an external domain (to prevent being exploited as an open relay).

Possible workarounds :

  • Contact the mail admin with the respective error code to check if the mail address is allowed to send emails to an external domain.
  • Mail server might require authentication for external relay. Provide the required username and password.
  • For unauthenticated access, create a new (anonymous) receive connector on your Exchange Server.
  • Give access to Network Configuration Manager's server in mail server by adding its IP/Hostname to the created connector.
  • Configure exchange to accept emails for multiple authoritative domains if required.

Mailbox storage size limit has been exceeded

Error Code :

  • 554 5.2.0 STOREDRV.Submission.Exception:
    SubmissionQuotaExceededException; Failed to process message due to a permanent exception with message The message could not be submitted because the sender's submission was exceeded.

Cause :

  • The Mail Server's Mailbox has reached its limit, there is no more storage space for storing or sending new emails in Office 365.

Possible workarounds :

  • Modify the delivery limits for outbound connections in Office 365.
  • May require some mailbox configurations. Please contact your mail admin with the error code.
  • Please refer this document for additional information.

Use an account that authenticates the From Email ID

Error Code :

  • 554 5.2.0 STOREDRV.Submission.Exception:
    SendAsDeniedException.MapiExceptionSendAsDenied; Failed to process message due to a permanent exception with message Cannot submit message

Cause :

  • The account details entered is not authorized to send emails as the designated From Mail ID.

Possible workarounds :

  • Use the same email address given in User Name as From Mail ID.
  • The authentication provided should be able to authenticate/authorize the entered From Mail ID.
  • If the same exception is found, refer this link.
  • This may require mailbox configurations. Please contact your mail admin with the error code.

Recipients Mail Address have rejected Mails from the Sender

Error Code :

  • com.sun.mail.smtp.SMTPSendFailedException: 554 Mail fromrejected for policy reasons.

Cause :

  • The From Email ID may be listed on the recipient's black list.
  • Error received from any of the Recipient's email address.

Possible workarounds :

  • All messages received via SMTP will be rejected unless the recipient's address is intended for the domain that appears in the Local internet mail domain's field. If the message is not intended for local delivery, add the sending server's IP address to the relay allow list.
  • Contact the mail admin with the error code for more details on the actual issue.

4. Memory Issues :

Unable to connect to the SMTP Server

Error Code :

  • 452 4.3.1 Insufficient System Resources

Cause :

  • Mail server would have been detected with insufficient disk space.

Possible workarounds :

  • Check if the mail server has sufficient disk space and clean up the trash to free space in the disk memory.
  • Disk space issue can be managed by moving mailboxes, clearing logs from the disk, or deleting unused files from the drive.
  • Reduce the amount of memory being used by all other processes.

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