Why Do My Email Messages Look Different When Received?
Prefinery doesn't do anything which would affect the readability of your email in different email clients. We simply send along exactly what you've designed.
Unfortunately, HTML email is a difficult beast to master. Unlike HTML for web pages, there is very little standard at all. And, matters are complicated by the fact there are tons of email clients, all reading email a bit differently. So, what looks good in Gmail or online (and email almost always looks better online since browsers are way better than email clients at rendering HTML and CSS) can look terrible in Yahoo or Hotmail or Outlook.
We recommend passing your HTML email code through a service which can analyze the code for potential problems. Litmus and Email on Acid are two services which can analyze your HTML emails.