Mail adds my signature inside the message, not at the end

zenqi wrote:

When I'm finished composing an email and add my signature, often my signature is placed in the middle of my message, not at the end. I have to copy my signature, delete it where it is and paste it at the bottom. This has happened very randomly but hundreds of times. Sometimes it's when a cut and paste is in the message, sometimes not. There seems to be no pattern or common denominator. It makes no sense to me.

—Try deleting the signature create a new one— maybe more simplifed or different in some way to compare your results.

—make changes to preferences Mail>Preferences>Signature

Create and use email signatures in Mail on Mac - Apple Support

you can submit your Apple Feedback/file a bug report: Product Feedback - Apple

Create and use email signatures in Mail on Mac - Apple Support (CA)

This would pertain to Text Based Signatures

Are the message you are writing all composed of typing vice copying/inserting text or images from other places?

As a test try creating a new signature and see if that gets inserted at the end.