I wish to email a pdf - if the recipient makes changes to it will it remain unchanged in my sent email as a record?

Hi,

I would like to send a document as a pdf as an attachment in an email.

If the person who receives it makes changes to the pdf, will my original pdf in my sent email which is kept in my sent box stay the same as it did when it was sent?

I'd like a record of the original pdf - so it anything arises where it is changed after I sent it I will have the original copy I sent to show what I sent.

Many thanks in advance for replies :)