We changed our micro instance to a small within a VPC and now sending email is sometimes fast and quite a lot of the time very very slow. Its as if our web pages are going to hang and then they eventually complete and sometimes the emails don't appear to arrive.
Also, I had to change the .net code which sends them emails because I was getting an error. I had to start disposing the SmtpClient class. I've never had to do this before! The error went away but the slowness remains.
What might have caused this?
When I do not dispose of the SmtpClient, I get the error...
'Service not available, closing transmission channel. The server response was: Timeout waiting for data from client.'