Add hash in mail

Why?

Many require proof of postage for files. Adding a SHA-2 or SHA-3 type hash (please avoid md5 and SHA1, prefer min. sha256) to the mail helps verify the integrity of the file.

What?

1. In settings,

• Add an option : "add a hash"
• (Add hash type choice)

2. When a file is attached, if necessary,

• calculate its hash, and
• add the text "HASHTYPE: calculatedhashkjhzjsdflkjsfdkjsddfhkjqshf" in the email under the download link.