title: Avoid being blocked by web mail companies for mass/bulk emailing?
body: <p>Our company is sending out a lot of emails per day and planning to send even more in future. (thousands) Also there are mass mailouts as well in the ten thousands every now and then.</p>
  
  <p>Anybody has experience with hotmail, yahoo (web.de, gmx.net) and similar webmail companies blocking your emails because "too many from the same source in a period of time" have been sent to them?</p>
  
  <p>What can be done about it? Spreading email mailouts over a whole day/night? At what rate?</p>
  
  <p>(we are talking about legal emailing just to make sure...)</p>