This can happen when your email is too long. Gmail considers any emails with an HTML size of over 102Kb to be too long so it cuts the message off at the bottom of the page. You would see a message at the bottom of the email that says “Message clipped” and a link to view the entire message as a webpage. This can be very frustrating for both the sender and the recipient. If Gmail cuts off the email it can also cut off the tracking code that determines if the email has been opened or not and it hides the unsubscribe link you need in order to be compliant with the law.
Here are some tips to keep your emails short and sweet and avoid this.
Cut content by including “read more” links to external sources.
Include an “Interesting links” section to reduce content.
Send smaller, targeted emails to your contacts.
Choose a template with multiple columns.
Get rid of necessary carriage returns and styles to reduce the amount of HTML.
What do you do to control the length of your email?