Microsoft announced on Thursday that Samsung Focus 1.4 owners will start to see the Windows Phone 7.5 “Mango” update shortly.

The software giant has started to deliver the Windows Phone 7.5 update to AT&T Samsung Focus revision 1.4 owners. Samsung Omnia 7 owners on Telefonica in Spain is in the scheduling state, expected to start being pushed in the coming days. “Expect us to expedite the scheduling process, now that it’s been fully tested,” said Microsoft’s Eric Hautala in a blog post on Thursday. Microsoft revealed in late October that it is delivering Windows Phone 7.5 to 100% of eligible devices.

Microsoft also took the opportunity to detail the new Windows Phone 7740 build. The update brings the operating system version up to 7.10.7740.16 and appears to be available for a variety of devices. Build 7740 addresses some issues with Microsoft Exchange 2003 and a voicemail notification problem:

• Fixes an email issue related to Microsoft Exchange Server 2003. With this fix, when you reply to or forward a message, the original message is now included in your response.
• Fixes a voicemail notification issue

Vodafone, Orange and Deutsche Telekom customers in Europe will start to see the update shortly. The Windows Phone service release, called 7740, addresses an important issue with new voice mail notifications not appearing for customers on some European and Asian networks. “This service release is being assessed by other mobile operators,” explained Hautala.

The usual Windows Phone 7.5 firmware updates are also rolling out to select devices. Nokia is planning to push its 7740 update in the coming weeks to address a battery problem with the Lumia 800 after it fully discharges. A Nokia spokesperson revealed to WinRumors on Thursday that the update is currently undergoing carrier testing and should be made available shortly. A range of other firmware updates are also avaialble for HTC devices. The HTC Mozart and HD7 both received updates this week to enable the Internet Sharing feature of Windows Phone 7.5.