I'm new to Apple Mail, having used Spark for years until this week.
I just used the Mail Drop feature for the first time and noticed that when I checked for the message in my Sent folder, it started to download the attachment; all 1.8GB of it!
I realise I can turn off attachment downloads, but I'd still like smaller attachments to be accessible.
One thing I've considered is using a folder trigger to delete attachments over a certain size from ~/Library/Containers/com.apple.mail/Data/Library/Mail Downloads.
However, it would be preferable if attachments (e.g. >20MB) didn't download in the first place.
My only thought is probably exactly the same as the conclusion you have maybe already come to: Mail Drop makes it simple to send large attachments but as it downloads them automatically (especially on the receiver's computer) it's probably better to send large attachments using a service like WeTransfer or a Dropbox link.
EDIT - Mail Drop works really well if you have just gone slightly over the attachment size limit - in which case it avoids you having to think of a way to send the attachment. So it does certainly have it's uses!
I have a lifetime subscription to Droplr that I was able to pick up years ago at a very reasonable sale price, and I like to use it when providing large files to people, because I can set them to self-destruct after a period of time and forget them.
I used to use Dropbox, but but the free plan leaves a lot to be desired – and I refuse to pay their exorbitant prices for higher tiers.
I managed to get 20GB of Dropbox space on a free account by literally buying it for about £4 on eBay. I think they automate referrals. Bit sketchy but it works. I prefer not to use Dropbox for sending large files though as I don't want to have to administrate files after they're sent. Wetransfer is my go-to, and it would be great if there were a way to send files directly from the Finder without having to use the app, but dragging something to the menubar icon is automatable so it's fine. I'd love the idea of Mail Drop, if there were a bit more control over whether or not files are automatically re-downloaded.