Error message when sending email
Recently I've been experiencing the following error when attempting to send emails:
"An error occurred while sending mail. The mail server responded: 4.2.0 Internal queueing error. Please check the message and try again."
I'm using Thunderbird (52.3.0) as my email client. The error does not happen consistently, but when it does, it forces me to attempt to send the email multiple times before it is actually delivered.