I notice now that I am using two computers temporarily until I get everything moved over to my new MBP, that when I get email in one I get it in the other. But when I delete it in one, the other computer still has it. Is there a way to delete from one and have it deleted from the other computer and my iPhone? I don't want to have to delete 2 or 3 times.

Thanks.

Are those POP or IMAP accounts. Look in Mail > Preferences > Accounts and that will tell you the type of each account.

IMAP

As you thought, with IMAP, deleting a message on one device should delete the message on all devices assuming the deleting device is connected to the internet when the deletion occurs.

However, there may be a delay before the deletion appears on the other device. The length of the delay depends to a certain extent on the speed of the internet connection but it is primarily a function of the account refresh rate or how often does is the account queried to check for changed, new, or deleted messages. See Mail > Preferences > General > Check For New Messages

NOTE: If your internet connection is slow a frequent check rate can have a noticeable deleterious effect on internet performance.

I didn't know checking frequently would do that. I put it back to every hour instead of every 5 minutes. Also, I rarely check email from my phone so I think I will disconnect that. Thanks.

The big risk there is mixing POP and IMAP. If POP checks for mail just after a message arrives at your mailserver, it will download it and may be configured to immediately delete it from the server. In that case, no IMAP (or other POP) devices will see the new message.

IMAP by default leaves all messages on the server the same as they are on the computer. The server and ALL imap clients are kept synchronised. If something changes on one IMAP client (and so help me if auto correct changes "imap" to "map" ONE MORE TIME imagonna...) the change will be performed on all other IMAP devices as soon as they connect to the server (for their next new mail check)

Interesting. I only have iMap accounts. I just got an iCloud account and it doesn't say which it is. I have had instances where I didn't get someone's email but that could have been on either end, I guess.

Your iCloud account is IMAP.


Either end or in the middle. Given all the things that can go wrong it an email, it is amazing to me how much actually gets through. (Often so much gets through I am tempted to wonder if Murphy's law hasn't been repealed — and then an absolutely critical email goes astray... )

Thank you!