The issues you are having, may have reference to how you are inserting CSS into your email marketing.
- In some email clients, they do not open CSS within
<head>
, so it is best to insert them within <body>
using the <style></style>
- On other clients neither inserting by
class
or id
will prevail, it is best to insert through the style=""
attribute%
But, all in all, what counts for one client is not guaranteed that it will work on the other, meaning in Gmail it can work but not in Outlook. That's why I recommend you read these guides on email marketing, you will have a greater sense of what you can and can not do in emails.
Mailchimp - Email Client CSS Support
Campaign Monitor - The Ultimate Guide to CSS