Gmail has a policy that ends up clipping message sizes larger than 102 KB.

Users receiving an email will notice a ‘View entire message’ link where the clipping occurs and will need to click it to access the full content of the email.  This common issue occurs with all emails being sent to Gmail addresses.

Methods to assist with reducing the size of the Email and Testing

1. Minimize Use of Images: The number of images can quickly consume a lot of space due to the amount of code used. 
2. When you change the size of an image, it may not reduce the size of the message.
   Message size is based on the total number of bytes in the email's code. Images loaded from external sources, such as through ContactMonkey servers, will not affect the size of the message, even though it will help with load times.  This is because the email only contains a reference.  However, deleting an unnecessary image from a campaign would remove the reference code, reducing the message size.
3. Avoid or Minimize Attachments: Instead of attaching large files directly to the email, upload them to a cloud storage service like Google Drive, Dropbox, or OneDrive and share a link in the email.
4. Reduce Text and Simplify Formatting: If your email contains a lot of text or heavy HTML formatting, consider simplifying it. Use basic styles and avoid unnecessary tags and inline CSS.
5. Send a test email using ContactMonkey's Test Email function: By sending a copy of the email to a Gmail account in your control, you will be able to see how Gmail will interpret and display the email
6. Limit the Use of Signatures: If your email signature is large or contains images, consider reducing its size or using a more straightforward signature.