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OMA is like OWA (Outlook Web Access) - it is a thin client where you can see your exchange mailbox, you open emails like a new web page.<br />
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EAS (Exchange Active Sync) is push email - it works in a similar way to a BlackBerry, in that is PUSHES email at the phone, and you open items as you would an SMS
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OMA is like OWA (Outlook Web Access) - it is a thin client where you can see your exchange mailbox, you open emails like a new web page.

EAS (Exchange Active Sync) is push email - it works in a similar way to a BlackBerry, in that is PUSHES email at the phone, and you open items as you would an SMS

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So why would a user need OMA if they already have OWA? &nbsp;Does it format the web page differently so it is more readible on a mobile device's small screen?<br />
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Also, for both OMA or EAS is port 443 the only port that needs to be opened through the firewall?
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So why would a user need OMA if they already have OWA?  Does it format the web page differently so it is more readible on a mobile device's small screen?

Also, for both OMA or EAS is port 443 the only port that needs to be opened through the firewall?

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Thanks. You are much better than Microsoft KB.
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Thanks. You are much better than Microsoft KB.

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I am having trouble figuring out the difference between ActiveSync and OMA. &nbsp;Could someone break it down simply for me. &nbsp;I've already read the MS white papers on the subject and they still don't distinguish the difference between the two very clearly.<br />
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Thanks.
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I am having trouble figuring out the difference between ActiveSync and OMA.  Could someone break it down simply for me.  I've already read the MS white papers on the subject and they still don't distinguish the difference between the two very clearly.

Thanks.

Difference between ActiveSync and Outlook Mobile Access

This topic area includes legacy versions of Windows prior to Windows 2000: Windows 3/3.1, Windows 95 and Windows 98, plus any other Windows-related versions including Windows Mobile.

Windows OS

Exchange is the server side of a collaborative application product that is part of the Microsoft Server infrastructure. Exchange's major features include email, calendaring, contacts and tasks, support for mobile and web-based access to information, and support for data storage.