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Open Settings.
Scroll down until you see Mail in the fifth set of icons and click on it.
In iOS 17:In iOS 18:
Accounts → Add Account → Microsoft Exchange.
In iOS 17:In iOS 18:
Enter your Zimbra email and an optional description, then hit Next.
When prompted, select Configure Manually.
Enter your Zimbra email and password.
You may required to type in additional information. If that is the case the screen will look like this. (Important: information for incoming and outgoing mail server will be the same.)
Name: Your name
Email: Your email address
Description: A name for the account
Host Name: mail.ossds.net
User Name: Your email address
Password: Your email password
Select options about what apps you want to sync with your Zimbra email.
Tap Save.
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