Add Post URL To Post (Custom Field) When Publishing?

Hello,

I use custom fields on my site for all posts. When publishing a post (before, during or after) is it possible to send the post’s own URL to a custom field in the post?

I send out a daily newsletter. Each morning I publish 20 posts, which are published to the website and to a page on the website which is imported to my Mailchimp email account – that page of posts (with images, excerpts, etc) is the basis of my daily email which gets sent out to subscribers. Each entry in that daily email has to link back to my site – but I don’t have the URL until after it is published.

So, currently, I am publishing each post, then opening the ‘edit’ post again, and the ‘view’ post, then copying the URL from the published post back into the edit post and republishing it with the URL. This adds 10-20 mins to my daily work – is there a plugin or hack that can do this for me? Or would it be possible for a developer to create something?

I send this newsletter 7 days a week, so a solution could save me over 2hrs per week.