K-9 Mail is not available for iPhone but there are plenty of alternatives with similar functionality. The best iPhone alternative is Microsoft Office Outlook. It's not free, so if you're looking for a free alternative, you could try Apple Mail or Spark. If that doesn't suit you, our users have ranked more than 25 alternatives to K-9 Mail and 14 are available for iPhone so hopefully you can find a suitable replacement. Other interesting iPhone alternatives to K-9 Mail are Delta Chat (Free, Open Source), BlueMail (Free Personal), Airmail (Paid) and TypeApp (Free Personal).
Delta Chat looks and feels like other popular messenger apps, but does not involve centralized control, tracking or selling you, friends, colleagues or family out to large organizations. "Privacy by Design" has never been more fun.
Airmail is a lightweight and lightning fast mail client for Mac. Feature list: Accounts: - Unified Inbox and folders - Multi Account with editable html signatures. - Aliases management with custom SMPT
TypeApp is an all-free, beautifully designed, universal email app, capable of managing unlimited number of mail accounts from various providers, allowing for smart push notifications while enabling personalization across multiple email accounts.
myMail is the smart email app for managing all your accounts on iOS and Android. Use myMail to manage messages in your Gmail, Hotmail, Live, Outlook, Yahoo, MSN, iCloud and AOL email accounts at once. The app also supports any IMAP and POP3-enabled mailbox.
Email by Edison (formerly Email by EasilyDo) is a brand new, elegantly designed, universal mail app to manage unlimited mail accounts from different providers including Gmail, Yahoo Mail, AOL Mail, Hotmail, Outlook, Exchange, IMAP, Alto, iCloud and more.