Mail App is crashing when receiving email with attachments

This issue started happening recently. I am sending emails using Gmail API through rest api, and when trying to open the email, the mail app just crashes and will not even open the email. I have tried sending email without the attachment, and it worked just fine. Could someone help me and see if the issue is with Mail App on IPhones, or just the way that Gmail API is attaching the files to the email. But, I can open the same email on browser just fine and even Android phones, but it crashes when it comes to only IPhone Mail App. Thanks!