As for rules, many email services, including iCloud, Gmail, and Exchange, let you create server-side rules to process mail before it even gets to your device. But it would be great if you could create local rules--including auto-reply options--on your iOS device, and possibly sync those rules with (and automatically grab new rules from) desktop Mail. At the very least, we'd love to be to edit server-side rules from our iPhones and iPads.
On-device junk-mail filtering
OS X Mail offers a decent junk-mail filter, and you can easily add a more-advanced third-party solution. But on your iPhone or iPad, you're essentially unarmed: Unless your desktop computer is on and processing mail all the time, or your email provider offers filtering on the server, junk mail arrives unfettered on iOS.
We--and many other people, if reader feedback is any indication--would like to see on-device junk/spam filtering. It doesn't have to be as good as, say, SpamSieve, and maybe it simply moves suspected junk mail to a folder that you can peruse at your leisure. But anything that cuts down on the number of unsolicited commercial messages we see in our inboxes would be welcome.
It's been seven years since iOS debuted, and we still don't have working address groups in Mail. Sure, you can create and use address groups in your desktop email client of choice; OS X Mail groups even sync to your iOS devices--but only as a way to more easily browse contacts. You can't use a group as a message recipient, and there's no way to quickly send to the members of a group. And, of course, there's no way to create or edit groups on your iOS device.
Those of us who need to send to groups have resorted to elaborate workarounds, such as setting up auto-forward rules on other email services, or even always having a draft, addressed to a group, saved in our Drafts folder in case we need to send to that group from iOS. Address groups is a no-brainer feature that iOS should have had in the 2000s, folks.
We've had pretty good luck using Gmail with iOS Mail (better than with, ahem, OS X Mail), but apparently not everyone has been as fortunate. Apart from the usual, and long-standing, wish that Gmail behaved as true IMAP, many people still have trouble with iOS 7 Mail not retrieving new Gmail messages without a significant delay. Others report problems with the way mobile Mail handles Gmail subfolders. So consider this a general request for iOS 8 Mail to be better at dealing with the hot mess that is Gmail.
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