I saw your column last week saying Apple’s MobileMe now does a better job of syncing contacts, calendar items and email. But will it allow me to sync to my iPhone directly from my company’s corporate calendar, address books and email?

MobileMe is meant for consumer data, not corporate data. Essentially, Apple’s own servers act like a company’s servers in order to bring corporate-style push syncing to consumer data that isn’t kept on corporate servers. To sync your corporate contacts, calendar items and email to an iPhone, you would use a different built-in option in the iPhone: Microsoft Exchange. Assuming your company’s IT department certifies the iPhone as an acceptable device, and your company uses Exchange, as many or most do, you can use an iPhone to perform instant two-way syncing of corporate contacts, calendar and email. It works just like a BlackBerry or Windows Mobile phone in this scenario. I have tested this, and found it worked well.

Is it possible to sync a Treo or BlackBerry using MobileMe? If not, how can I transfer my Treo contacts and calendar items to the iPhone?

While MobileMe is agnostic when it comes to computer platforms, working on both Windows and Macintosh computers, it is single-minded when it comes to handheld devices. It synchronizes data only to Apple’s own iPhones and iPod Touch devices. It doesn’t work with the Treo, the BlackBerry, or any other smart phone or handheld device beyond those made by Apple. One simple way to move contacts and appointments from Treo to iPhone is to use Outlook as an intermediary. First, sync your Treo to Outlook. Then, just plug your iPhone into your PC, launch iTunes, and sync the iPhone with Outlook. The data from your Treo should then be on the iPhone. MobileMe isn’t required.

I can’t find the location of the files contained in my Personal folders in Outlook that contain my contacts and saved emails. Can you help?

To find the location of the single combined Outlook data file that contains your email, contacts and calendar, follow these steps. First, select “Data File Management” from the File menu. A window will open showing the name of your data file, which includes its location on your hard disk. Click the button to the right that says “Open Folder,” and you will be in the folder that contains this file, with the file’s name or icon highlighted. Outlook data files use the extension “pst” at the ends of their names.

• You can find Mossberg’s Mailbox, and my other columns, online free of charge at the new All Things Digital Web site, http://walt.allthingsd.com.

I am in the market for a new HDTV and the newspaper ads are using terminology that I’m unfamiliar with. Do TVs rated at “720p” provide the same quality picture as those rated at “1080p”?

Technically, the answer is no, but it may not matter. The 1080p resolution is certainly higher, but almost nobody can tell the difference between the same material shown in the two resolutions on TV screens up to around 50″ in size and at the typical distances from which people watch those screens. Not only that, but most sources of video content, with the exception of Blu-ray discs, can’t even fully utilize 1080p. Major TV networks don’t use it yet because it requires a lot of bandwidth.

If you can afford a set that can handle 1080p, you might want to buy it so that you are ready in case a lot of 1080p content one day becomes available. You might also want a 1080p set if you are a videophile; have an enormous screen or a projector that fills a large wall; or if you play a lot of Blu-ray discs and believe you can discern the difference on a typical-sized screen. Otherwise, you could save money by buying a 720p set and you might never know the difference.

In 2006, you recommended a powerline adapter for Internet access by Netgear, the XE104. Is this still a good buy or are there others by now that are better?

I haven’t tested powerline adapters, the gadgets that route computer networks over standard home electrical wiring, since that date. Netgear and its competitors — such as Linksys and Belkin — have, naturally, come out with newer, faster units since then. But I am still personally using the XE104 successfully and feel I continue to get my money’s worth from it. It is still being sold. The newer units typically have greater speed in order to do a better job of streaming video around a home, but they work in basically the same way.

I have a Windows XP system, and things work well with my cable modem in my office. But when I’m on the road using Wi-Fi, I can receive emails, but can’t reply or send out. Any idea on how to resolve this problem?

This usually happens because the Wi-Fi provider is blocking the outgoing email server (called an “SMTP” server) that you or your IT department has set up in your email program. Some providers block all such outgoing servers. There are a number of possible solutions. The simplest is to use a Web-based email service, like Gmail or Yahoo Mail, or the Web-based version of your usual service. If your email is provided by your company, you may be able to access a version of Microsoft Outlook over the Internet that will work.

Another possibility is to ask the provider at the hotel or airport what SMTP server it does allow — usually its own — and enter it into your email program’s settings, if you know how. Yet another option would be to use a data card from a cellphone carrier, which I have found can usually overcome this problem. There may be other workarounds, and I invite readers to suggest them.

You can find Mossberg’s Mailbox, and my other columns, online, free, at the new All Things Digital Web site, http://walt.allthingsd.com.