An e mail had apparently not been despatched to me as a result of I did not see it on my cellphone. Checking on my MacBook Professional’s Mail, I noticed it had been despatched. Evaluating the 2, I realised that solely these in my Inbox on Mail have been showing additionally on the cellphone.

Why? I would created Mailboxes (folders) in my Mac Mail, similar to Accountant, or Robotic Stuff. For every I would carried out
Mailbox –> New Mailbox –> after which when it sought Location, I would defaulted to On My Mac, not exploring the drop-down choices.
I would then created guidelines to position emails as they arrive into acceptable mailboxes.
Had I as a substitute chosen my area for every of these new mailboxes, every could be reproduced on my cellphone.

I corrected it by dragging and dropping every mailbox from On My Mac to the area proven on the backside of the left sidebar. That copies the mailbox and any sub-mailboxes inside it and the email-messages inside. It reveals underneath Copying Messages, on the backside left of the window, a operating depend because the email-messages are copied.
As soon as the copy of a mailbox was full, I deleted the unique from On my Mac. The cellphone confirmed every such mailbox and its contents too.

The Guidelines although, nonetheless pointed to the outdated and now deleted mailboxes. Every needed to be edited to level to the brand new mailbox on the area.

Now emails acquired and seen on Mac Mail seem in the identical method on the cellphone.

Q.E.D.