Cannot send mail : no protocol

Setup, Configuration and Use Beginners
8

Thank you for doing all these trials but it did not work for me
If I use the “587” as the port in the UI, the code shows port: ’ “587” ’ but the binding ignores it and send the default port (25) which times out.

Here is my thing code entering 587 (no quotes) in the UI

UID: mail:smtp:dd7055cab0
label: SMTP Google
thingTypeUID: mail:smtp
configuration:
  hostname: smtp.gmail.com
  password: my app password
  security: STARTTLS
  port: "587"
  sender: xxxx@gmail.com
  username: xxx@gmail.com

here is the script

val mailActions = getActions("mail","mail:smtp:dd7055cab0")
mailActions.sendMail("xxx@yahoo.com","openhab","Test")

and the error

21:53:52.287 [WARN ] [hab.binding.mail.internal.SMTPHandler] - Sending the email to the following server failed : smtp.gmail.com:587
21:53:52.289 [WARN ] [hab.binding.mail.internal.SMTPHandler] - javax.mail.MessagingException: IOException while sending message;
  nested exception is:
        javax.activation.UnsupportedDataTypeException: text/plain; charset=UTF-8

If I remove the quotes in the code (port: 587), then the binding thinks it is a real number and sends 587.0 as the port which gives many errors