Problems with attaching signatures to emails

Diane,

Do you have the correct email account selected for the desired signature? Mail (El Capitan): Signatures preferences:

"Choose signatures to work with by clicking All Signatures or an email account."

In Mail -> Preferences -> Signatures

1. Click on "All Signatures" in the left column.
2. Click and drag the desired signature from the list in the middle column and drop it on the account in the left column.
3. Repeat for all the signatures that you want to use with that account.

1. Choose Mail > Preferences, then click Signatures.
2. In the left column, select the email account you want to use the signature for, then click .You can drag signatures from one account to another, or to and from All Signatures. If you create a signature in All Signatures, you must drag it to an account to use it.
3. In the middle column, type a name for the signature.The name appears in the Signature pop-up menu in the message header when you write a message.
4. In the right column (the preview), create your signature.You can use the Edit or Format menus in Mail to change the font or layout, turn text into links, or check spelling. To add an image, drag the file into the preview.