Aphexking wrote:
If I send an email and attach a picture, if I choose to show it as Icon, the receiver receives the email but no attachment in the email.
The recipient doesn't understand how to use their e-mail software.
If the same email is done with an attachment but not shown as an icon in the email, the attachment with the email is received.
Does anyone know why this is happening, thank you
E-mail is extremely complicated to begin with. Apple really doesn't help much. Just use the defaults and don't worry about it. Your message will be properly constructed. If the recipient has problems, the cause is almost always on their side. If you want to know more, keep reading. But I strongly recommend you stop reading here.
The only meaningful control you have over attachments is the choice to force them to be at the end or not. I don't recommend it. Otherwise, all attachments are the same. If the attachment is something that could reasonably be displayed as a single-page image, then it is attached so that it looks like a single-page image in your e-mail. Anything else, multi-page images or other files, are attached so that they look like icons.
Anything you put into an e-mail message is an attachment. They are all the same, in every way. When I talk about what they "look like" above, I am referring to one specific metadata field that reads either "attachment" or "inline". This is strictly a hint. Neither you nor your recipient really has control over how the attachment actually gets displayed. You can make your preferences known, but in virtually every case, your preferences will be ignored.
What makes this even more complicated is the fact that all of this is true, in duplicate, on both your computer and the recipient's computer. Plus, your e-mail goes through various e-mail servers. Any one of these can disassemble your e-mail, scan it for viruses, and then reassemble it. Sometimes they do this wrong and scramble it. This could happen on your e-mail server when you send it. It could happen on the recipient's e-mail server. It could happen somewhere in-between. It could also happen due to some 3rd party antivirus that either you or the recipient has installed on their computer.
The only real guarantee that you have is that Apple Mail is sending a correctly formatted e-mail. Regardless of anything else that is happening, when it leaves Apple Mail, it is correct.
Now it may not be what you intended. Apple Mail will lie to your face without even blushing. When you chose "show as icon", that only controls how the attachment displays in your new message window right then. It has absolutely no effect on the e-mail that will be send - none whatsoever. If your attachment is "image like" it goes out as an "inline" image - 100% of the time. Even if you try to force things by setting mail to send only plain text messages, again, it totally lies to you. Apple Mail sends HTML messages, regardless of your settings, 100% of the time.
PS: I forgot to mention. Recent versions of macOS are chock full of bugs. I looked at the raw source of the messages to confirm they were correct. I see incorrect displays of all these on both Monterey and Ventura. But those are just Apple display bugs. The messages themselves are formatted correctly.