If you are unable to add attachments to your emails, there are a few steps you can take to try and resolve the issue:

1. Check to make sure that the attachment meets the requirements of the destination email address.
2. Check to make sure that the attachment is in a supported file type.
3. Check the size of your attachment and ensure it is not too large for the email.
4. Restart your computer before attempting to re-send the email.
5. If possible, try sending the attachment from a different email address.