How new mail arrives
New mail appears in Mail within seconds of reaching your mail server, and the notification comes at the same time. How it works, what you need to do (nothing), and what to do when mail is late.
New mail appears in Mail within a few seconds of reaching your mail server. The open page shows it by itself, and the notification on your phone or computer comes at the same time.
How it works
The site keeps a line open to the Inbox of each of your mailboxes. The mail server uses it to say "a message arrived", and Mail fetches that message right away. Engineers call this IMAP IDLE; almost every mail server has it, Gmail, Yandex, Mail.ru, iCloud and cPanel servers included.
What happens next:
- The new message is stored with the others. Your rules run on it: sorting into folders, the black list, New senders, muted conversations.
- If it is important mail from a person, the notification goes to your devices (see Mail as an app).
- An open Mail page notices it within about five seconds and shows it at the top of the list. You do not need to press the refresh button.
Do I need to switch anything on?
No. It works for every mailbox you add. The site's administrator can switch it off for everyone in Settings → Mail → New mail at once (IMAP IDLE). Then Mail checks your mailboxes once a minute instead.
Limits
- Only the Inbox is watched this way. Sent, Trash, Spam and folders kept in step with the server are still checked once a minute.
- A server without IDLE (rare) is checked once a minute. Mail tries again a day later.
- Many mailboxes on the site. The site watches up to a set number of mailboxes at once. The rest are checked once a minute.
- Mail deleted or read elsewhere (in Gmail's own page, on your phone's mail app) shows here at the next minute's check, not at once.
Mail is late — what to do
- Press the refresh button over the list: it checks your Inboxes at once.
- If your mailbox shows an error in the gear → Mailboxes, its login no longer works. Change the password there (for Gmail, Yandex and others: a new app password).
- A mail server sometimes holds a message for a minute or more before it reaches the Inbox (spam checks, greylisting). Mail can only show what the server has.