Q: Can I set Apple Mail (OSX) to send ALL attachments using Mail drop? (A bit like using WeTransfer?)

Hi Algoz,

Thanks for using the Apple Support Communities!

I understand that you would like to use Mail Drop to save your attachments, even for smaller attachments. 

There is no way to manually upload an attachment using Mail Drop; it works automatically as described below. 

Add an attachment

1. While writing a new email message, click the Attach button  at the top of the message window. 

2. Select the files you want to attach, then click the Choose button to begin uploading the files.

    

   If your attachments are too large to send in email, iCloud Mail asks if you want to deliver the attachments using Mail Drop. If you agree, Mail Drop uploads the attachments to iCloud. 

    

   To select several adjacent files, click the first one, then Shift-click the last one. To select multiple nonadjacent files, Command-click them on a Mac or Control-click them on a Windows computer. 

    

   When the upload is complete, the attached files are listed above the message you’re writing.

    

   To attach more files, repeat steps 1 and 2.

Also, recipients can download Mail Drop attachments for 30 days after they are sent (also outlined in the following article), so this may not be the type of storage solution you are looking for. 

iCloud: Add an attachment to an email

Best!