Mailbox unavailable. The server response was: No such user here

When you send email from an application, most SMTP servers require authentication. Your application needs to supply a valid username and password to be able to connect to the server. This prevents strangers to use your SMTP server and send millions of spam emails. When your application does not supply the correct credentials to connect to …

Unable to read data from the transport connection: net_io_connectionclosed.

When your application tries to send an email using a Gmail account you may get the error message: Unable to read data from the transport connection: net_io_connectionclosed. One of the causes can be, when “Less secure apps” are not allowed to use the Gmail account. To enable “Less secure apps” to use the Gmail account Log …