Sending Caravans

+1, and while at it the delete mail function (as it is, not as it should be) needs an undo, bumping my own vans and deleting the wrong mails are my favourite errors. 

The trade accept button is a different story.  If recall isn't okay for ordinary harvesting issues another solution would be to provide more info in the "send" form:  How long will it take to get to the target, and are there already other vans on the way to or harvesting at the target?  At the moment the "send" form only allows to pick one or more vans, but offers no detailed info.

For the mail delete undo it's similar:  If I could delete a system mail while reading it I wouldn't need an undo. But as it is I have to quit the mail, then find it in the list, select it, scroll down, and click delete.  Problem is, I sometimes select the wrong mail, the subjects are similar or sometimes identical, e.g., "spy mission to new settlement successful".

After figuring out that this old "new settlement" is now an even newer settlement with a rainbow the message can be deleted.  But there are several of these messages in the list, which is the one I want to delete?