I have been using Quail for weekly newsletter delivery since the brand reposition to Warm & Wise . However, the subscriber management is mush simpler on Quail than other service.
By studying the email blasting service I had taken, I decided to move the subscription form to Acumbamail, which is one of the best email marketing tool I have used, supporting html code embedding and also the full-functioned subscriber management.
Will keep using Quail for weekly newsletter, one annoying steps is have to add the new subscriber to Quail manually.