For any e-mail to be effective, we have to take care of few aspects. Before discussing about the aspects of the e-mail, let us go through the important parameters of E-mail.
Sender: From which e-mail id are you sending the e-mails. Please check your name and details in that e-mail. Because you are the sender of the e-mail.
Subject- Check the subject of the e-mail. The most vital part of the e-mail. Do not mention unnecessary things in the Subject line.
Context and Design: If you are sending an HTML template e-mail or even text e-mail make sure that your context and design of the e-mail are perfect.
Content: The major element of any e-mail is the e-mail body content.
Links: Check out the links associated with the e-mail. It may be to your landing page or signup page.
Header and Footer: The e-mail template header & footer should be good, it should look professional.
Images: If you have added any images in the e-mail, then check out the responsiveness of the image. The resolution, look & feel should be good.
Before sending the e-mails always TEST-TEST-TEST the e-mail with complete specifications, whether you have everything correct or not.