Absence of Mail Notification for undelivered messages.

Question

I have recently sent some important mail messages with attachments, they never arrived and I didn't get any notification to let me know. I have looked and can't find anywhere that I can 'switch' this setting on. As far as I am aware they were within the size limit but I have noticed that even if messages with attachments are just slightly less than the allowed size they won't even leave my mailbox. Is there anything I can do about both these problems. Thank You.

Answer 1

There a few issue here. First, if an e-mail doesn't go through, it's up to the server that didn't hand it off to send back a message to inform you of it. There's nothing to do in Apple Mail (or any other e-mail program, for that matter) to set in order to request notification. It's quite possible that a server botched handling mail along the way, and it's far more likely that mail was not delivered because something in the message cause SPAM-blocking software to throw it out (these days, that's the most likely scenario), in which case you'd never be notified.
Mail has no limit on the size of messages. Your Internet service provider may have limits, and the recipient's e-mail service may also have limits. What happens if you go over the limit is really up to the mail services involved. Your local service provider is likely to return an error to Mail at the time you attempt to send it, indicating that it can't be sent. Your recipient's mail service could: throw the message away, strip out the attachments, or return the message back to you with an explanation why it's refused. There's no rule to state that the recipient's mail service has to do anything in particular.
Generally speaking, for anything other than a trivial image, you want to place the file in some web-accessible location and then send a link to where the file can be retrieved.
Also, keep in mind that when you attach a file to an e-mail message, it grows in size by 35%. This is because e-mail is a text-only service, non-text data needs to be converted to text for e-mailing and the conversion method is called "base-64 encoding". Base-64 encoding uses 4 letter to represent every 3 bytes of data in a file (and it adds a few extra characters). So, if you attach a 10M file, your e-mail attachment's actual size will be 13.5M.