This method works best for multiple images (up to 10) for the same orientation (portrait or landscape).
Step 1: On your computer, attach up to 10 images of the same orientation - either all landscape or all portrait - to the body of your email.
Step 2: Write your caption in the body of your email.
Step 3: Add any hashtags at the bottom of your caption of your email.
Step 4: Send email to yourself.
Step 5: Go to your phone and find email.
Step 6: Download all images from your email.
Step 7: Highlight and copy caption and any hashtags from the email.
Step 8: Go to your Instagram app and click to add all your images.
Step 9: Enter details in all the usual fields in Instagram and share.