Right-click on the signature file and choose Open With >TextEdit. mailsignature, having a load of letters and numbers as the file name. In the Signatures folder, locate the newest file that ends.Select the latest V folder, and then the MailData folder. The quickest way of doing this is to go to your Finder and in the top menu bar click Go > Go to Folder and enter ~ /Library/Mail/.

Drag the signature from the second column to the email account you would like it to be available to, if you have multiple accounts.Make sure, that the Always match my default message font box is unchecked.> Select Preferences in the drop-down menu. Create a new email (File > New message) and select your new signature from the Signature drop-down menu.The signature in the preview may seem disrupted, however, it should look completely fine when you start composing a new email. Go back to Apple Mail > Paste the signature into the signature box.Under the Info tab, click the signature you would like to use, then press.Go to AdSigner > Users > Click Actions of the user, whose signature you would like to use > Click Manage Signatures.Make sure that the Always match my default message font box is unchecked.Then, move to the Signatures label > Choose All signatures, if you want the signature to be available to all accounts, or select a specific one > Click + button to add a new signature and name it.

Navigate to the Composing label > Under the message format, choose Rich text.

Choose Mail in the main menu > Select Preferences in the drop-down menu.

Update it in the AdSigner and set it up again in the email client. Do not make any changes of a signature after pasting it in your email, as the predesigned form of the template might collapse.

How to add signature in mail app