Several users have reported problems with the Mail app. Specifically, some users are experiencing serious problems in viewing emails with attachment using the mail app after updating to iOS 9. They receive the following error message when they attempt to open an email message:
- This message has not been downloaded from the server error
It appears that this issue is affecting POP email accounts and all iOS devices.
If you are unable to open / send / receive emails with Mail on your iPhone, iPad, or iPod touch, here is how you can troubleshoot:
1-Tap Settings > Mail, Contacts, Calendars > your email account > Advanced >Delete from server > Set to Never, under INCOMING SETTINGS.
2–Restart your iOS device.
3-Reset your network settings by going to Settings > General > Reset > Reset Network Settings.
4-Remove your email account and then re-add. To do this, tap Settings > Mail, Contacts, Calendars > Your email account > Delete account. Then add your account by going to Settings > Mail, Contacts, Calendars > Add Account.
5-Switch from POP to IMAP. To do this, ensure that (a) your email host/service support IMAP (b) your know your IMAP settings, simply contact your email service provider to find out your IMAP settings . Then disable your POP account by unchecking the Account setting (Settings > Mail, Contacts, Calendars > Your email account). Now create your IMAP account.
6-If trying fixes above does not fix your problem you may want to use an alternative email app until Apple engineers fix this. Some email apps you may use are: