Recall Sent Mail

Same way you recall a snail mail, you can't.

And with email once it leaves your computer you no longer have control over it as it passes through multiple nodes to reach its destination. And the protocol does not include any way of doing this.

Call the recipient and apologize for sending that inappropriate email.

"In this day and time..." has nothing to do with it. Not being able to recall sent email has nothing to do with Mac. If the email protocol does not meet your needs then don't use email.

To get where you want and assuming the recall will be honored—it won’t be—you’ll need to upgrade millions of different mail servers, across hundreds or thousands of different operating systems and platforms and versions, running any of dozens of common mail server programs and hundreds of other and less common servers, and these run by hundreds of thousands of folks, across hundreds of countries and millions of organizations.

That’s all assuming you can send a unique deletion request, and to remain reasonably immune to snooping using faked recalls, and spoofing of recall requests, too.

We’ll get right in that internet-wide upgrade for you.

Right after we finish with the IPv6 upgrade that is, which has been going for decades. And will continue for the foreseeable future.

Yes, Exchange Server can be configured to allow message recalls, but only for messages remaining within the mail server. Attempts to recall messages that have left the Exchange Server send a nice recall message to the recipient of the original message, and which then causes pretty much everyone to go read the recalled message.

More than a few folks will block recall into their mail servers, assuming those servers are eventually updated to support message recall. Just as soon as anyone sends this hypothetical future recall request, most folks will preserve and read the recalled message.

No, you cannot.

Because of the way the email protocol works. There is nothing defined in the protocol to do that.

It would also be delivered before you could recall the message. Theoretically, an IMAP server could attempt to remove the message if it had any way to keep track of the message the recall referred to. On a POP account, once downloaded by the recipient, there is no way to get it back.

Standard E-mail protocol do not have that option.

Once sent it's out of your control.

It would be delivered before you could recall it most likely... anyway your "recall" would never catch up to the "sent" one. :)