A bug fix may be in order.
Since its release on September 16th, a number of iOS 9 users have reported having trouble opening emails with attachments. There’s currently a 22 page thread on the Apple discussion forums covering the issue, which currently has more than 200 replies from users who are all experiencing the same problem.
The issues, which cover a wide range of devices, often report a “Message not yet downloaded from server” error whenever they attempt to open an email message with an attachment. The problem appears to be affecting Apple customers who have POP email accounts and is causing issues with both new and old emails.
Deleting email accounts and adding them back in does not fix the issue, but downloading an alternate email program from the App Store seems to have worked for many users as a temporary fix. Turning off Wi-Fi also allows some users to read their previously downloaded emails and access attachments, but images are not viewable.
One customer experiencing issues received a response from Apple’s engineering team, suggesting the email issue occurs when an email account has been configured to remove a copy of emails on the server. This has left some wondering whether the behavior is an intended function or a bug, but while leaving messages on the server solves some of the problem, sent and trash emails remain unaccessible.
A reply from Apple’s engineering team contained the following advice:
iOS leaves messages on the POP3 server by default. iOS never stores email permanently, whether POP3 or IMAP. If they are removed from the server by another device then this issue can occur.
A test that you may want to do to confirm this is to have the customer produce the error by opening one affected mail on the iOS device, and then locate that specific email on his webmail. If not found, then the device is behaving as expected. If found, please try to forward it to the same mailbox and see if the same issue occurs.
Apple has yet to fix this problem in either the iOS 9.0.1 or 9.0.2 updates that have been release. It’s presently unclear if the upcoming iOS 9.1 update will resolve the issue.
Apple has yet to release a comment as to the issue.
Stay tuned for additional details as they become available.
Via MacRumors and Apple discussion forums