When your website users land on a page that solicits their personal information, tradition might tell you to include a pre-checked box that opts the user into an email campaign so they can receive updates and special offers related to your business. Today, having this box pre-checked is in violation of GDPR. So, to comply with GDPR, make sure your European users and customers are given the clear option to opt into your email newsletter themselves -- don't make the decision for them.
When it comes to deciding how to craft that perfect subject line, there appears to be really only one area to avoid: the subject line of 60 to 70 characters. Marketers refer to this as the “dead zone” of subject length. According to research by Adestra, which tracked over 900 million emails for its report, there is no increase in either open rate or clickthroughs at this 60-to-70 character length of subject line.