Apple Mail 16.0 transmits message but not attachment

You might want to double check the maximum size allowed for attachments from you mail provider. Normally when they exceed the limit, no errors are given. As a test, try attaching smaller attachments to see if they work. Normally the size limits are between 20-30 megabytes.

What is the email service you used that it didn't arrive from? Perhaps you can check with them or check your settings on that account using their web portal access to your email account. It sounds more like an email service provider issue more than it is an Apple Mail issue.

Martin Hayman wrote:

Worrying: Apple Mail sends a message I compose, but the attachment is not received by the addressee.

How do you know this? If the attachment really didn't arrive, then the most likely explanation is that the recipient's e-mail server blocked it.

People aren't necessarily reliable. There can be many reasons why they would say that to you. Maybe they didn't see the attachment. Maybe the attachment was blocked. You don't know. A message composed from one client may be treated by a spam filter completely differently than a message composed by a different client.

Here's the thing. If Apple Mail couldn't send attachments, don't you think someone would have noticed at some point?

Unfortunately, e-mail is complicated and e-mail software is even more so. If you could get the recipient to send you the original message that they received, it would help diagnosing the problem. But even that would be practically impossible for all but the most advanced users. It's just a click and a menu selection, but this is 2023.

I don't know what to tell you other than Apple Mail can most definitely send attachments. But since your recipient is the one having the problem, it is their responsibility to figure it out. Depending on your power relationship with said recipient, it may become your problem. It's probably a bigger socio-economic problem than a technical one.

Maybe the problem is the format. Scanners often create bitmap documents and sometimes use the TIFF format. This is essentially the native Mac image format. But most PC users will not be able to open a TIFF, especially one that uses any kind of funky encoding.

Martin Hayman wrote:

Ah I think I see what the issue may be. Original scan came in at just shy of 1 MB, but I sent it 'View as Icon',

I'm sure it was something else. Many people over many years have been confused over the "View as Icon" feature. It does nothing. Absolutely nothing. Never has.