Why is my SMTP Integration not working over port 587?

When configuring SMTP Integration with Managed File Transfer over Port 587, a username and password will need to be provided, for the connection to be authenticated.

To validate the configuration, the application will attempt to send a test email using the administrator (that is saving the changes) email on behalf of the configured user. If this fails, an error message similar to the one below will pop up:

And an error message will be generated in the logs:

• This will mean that the SMTP Server received valid credentials, but the MFT Authenticated User does not have the permission to send the email on behalf of the Configured User

To address this, it is very important to understand that the configured username will need to grant access to anyone (the MFT users) that will need to send emails on behalf of it.

The best and recommended way of achieving this is by configuring a Central Relay Application, so that it will be able to intercept MFT’s request and send it to the SMTP in a way the server will accept it. The typical flow will look like below:

1. The MFT Server makes the HTTP POST Request:

   1. To the relay application
   2. With email data: From, To, Subject, Body, Attachments

2. (optional) The Relay Application checks the sender’s permissions

3. The Relay Application connects to the real SMTP Server using one service account

4. It sends the email on behalf of the specified “From” address

Additional details about SMTP and Notifications can be found at the addresses below: https://www.opswat.com/docs/mdmft/configuration/notifications