How do I fix SMTP Error 535?

Methods To Resolve “SMTP Error 535 Authentication Failed” Message

  1. Firstly, you should log in to your control panel and check your current account status.
  2. Check the username and password provided to log in to your mail server.
  3. Block the IP addresses that are consistently trying to log in to your account.

How do I fix mimecast error?

How can we resolve general issues with Mimecast for Outlook?

  1. Close Microsoft Outlook.
  2. Ensure the msddsk.exe process isn’t running in the Task Manager. Stop it if it is.
  3. Navigate to the “%userprofile%\AppData\Roaming\Mimecast” directory, and delete the msw. s3db file.
  4. Re-open Microsoft Outlook.

What is 535 Invalid user ID or password?

This error can have two meanings: The username and password that you have entered into your program are incorrect and you are failing authentication. Your account has been disabled because of a problem. You are using IP based authentication and your account has been disabled or has expired (uncommon)

How do I authenticate on Mimecast?

Article Details

  1. Select the Mimecast ribbon.
  2. Select the Account Options icon in the General section. The Authentication Settings dialog is displayed:
  3. Select an Authentication Option.
  4. Enter your Password.

How do I fix Mimecast in Outlook?


  1. Click the File tab.
  2. Click on the Options menu item.
  3. Click on the Add-Ins menu item.
  4. Select COM Add-ins in the “Manage” drop down list at the bottom of the dialog.
  5. Click the Go…
  6. Ensure the Mimecast for Outlook add-in is enabled.
  7. Click on the OK button to close the window and return to Microsoft Outlook.

What does 5.7 0 authentication required mean?

The server response was: 5.7. 0 Must issue a STARTTLS command first: This error means that the transport layer security (TLS) needs to be set to “Yes” in your SMTP settings. The SMTP server requires a secure connection or the client was not authenticated.