Well, there used to be a feature in the iPhones that allowed to save up on the space consumption by limiting the number of POP/IMAP emails (read Yahoo or Gmail accounts) that showed on the iDevices. But with the advent of iOS 7 this feature has somehow vanished!
Now, Apple users are experiencing a rush in the unread messages, reported even close to 4000, that remain unread, and limit the use of valuable storage space by other apps. The recent updates till 7.1.2 have not yet addressed this much talked about elimination.
While you could delete the messages, they might pop back up, if they are still on your server. And you wish to keep your huge collection of emails, thinking they might come in handy at a future date, here’s one workaround on How To Limit Number of Emails on iPhone.
Step 1: Go to Mail.
Step 2: Select the inbox you wish to limit.
Step 3: Tap on Edit, on the top-right corner.
Step 4: Tap Mark All, on the bottom-left.
Step 5: Say Mark as Read.
Once the account is refreshed, the huge memory consumed by unread emails will clear off.
Well, there’s another way by which you can restrict the IMAP messages in your folder. Now this can be done only through your mail server.
Step 1: Login to your mail (Gmail in this case).
Step 2: Go to Settings icon on the top right of the page.
Step 3: Drop down and select ‘Settings’.
Step 4: Click on Forwarding and POP/IMAP.
Step 5: Scroll down to IMAP Access -> Folder Size Limits. Here ‘Limit IMAP folders to contain no more than this many messages’ to 1000 and save the changes.