HTML Email template - formatting issues

Summary

When creating the email templates, our formatting is very different to what is displayed in the email template preview

Content

Hi, 

We are currently creating email templates using manage html templates and find that all test emails that are sent out are badly formatted once the preview goes through to the test email account (using outlook and gmail) . E.g. the email columns do not line up, what is centred in the template becomes aligned to the left. 

Has anyone else experienced this?

What have you done to counteract this?

Thanks! 

Nirupa