Troubleshoot a Mac OS X Mail.app that Won’t Open

by Matt on December 23, 2011

You’ve run into a problem: the Mail icon bounces endlessly in the Dock (and the pointer may or may not change to a spinning beach ball), or it unexpectedly quits and presents you with a window indicating such. How can you solve this frustrating event?

Perform the following steps—in order and one at a time—until you solve your problem. The solutions increase in severity (in terms of potential data loss), so you want to stop once Mail will open. Create a new folder on the Desktop before you begin, as steps 2-4 require you to temporarily remove files from existing folders, and storing them on the Desktop allows you to quickly restore your data.

Accessing Your Address Book

Mail needs to be able to access the contents of your Address Book, even if it is empty. If Mail will not open, there is always the chance your file permissions are simply incorrect. If you no longer have the ability to open the Address Book or modify its entries, select Address Book in the Finder. From the File menu, select Get Info. The window that appears will have a section called “Permissions.” By default, you should see three names listed in the “Name” column: system, wheel, and everyone. Make sure system has “Read & Write” privileges. Alternatively, you can click the plus button and add your user to the list, making sure it has read and write privileges. You may need to click the padlock at the lower right corner and enter your administrator password to make these changes.

Managing Mail Plug-ins

If Mail still will not open, you may have installed a plug-in that is now corrupt or incompatible. Navigate to the InputManagers folder inside the top-level Library folder. If there are no items in this folder, proceed to the next troubleshooting step. Otherwise, drag all of the items from this folder to the new folder you created on the Desktop, and reopen Mail. If Mail opens properly, one of the InputManagers is the culprit. You should place one InputManager at a time back in its folder, restarting Mail each time, until Mail no longer opens. The last InputManager replaced is the one causing the problem. You can try updating to a newer version, reinstalling the existing version, or simply removing that file to solve the problem.

Changing Mail Preferences

Mail’s preferences may also become corrupt. To test this, navigate to your user Library folder and open its Preferences folder. Move com.apple.mail.plist to the Desktop. Try reopening Mail. If Mail does not open successfully, the preferences were likely not at fault. However, Mail may have created new preference files when you tried to open it. You should move your old preference file from the Desktop back to the Library Preferences folder (choosing to replace the existing preferences, if necessary).

If removing your Mail preferences did allow Mail to open, this presents a slightly more annoying problem: your email data remains intact, but your settings disappear. While you lose small settings, such as font preferences and window sizes, Mail also “forgets” that you have email accounts installed. If Mail cannot find any existing accounts, it first tries to configure your MobileMe account, assuming you have registered it in the MobileMe System Preference. Otherwise, Mail opens to its configuration window and asks you to enter your email account details. After entering this information, your existing email messages and folder may have returned, but if not, continue reading to learn how reinstall your folders.

Checking Mail Folders

It is common for Apple’s Mail to store hundreds of thousands of files in its data folders, especially if you keep all of your mail from years ago. Fortunately, it is uncommon for these files to become so corrupt that Mail no longer opens. There is an easy way to test this, however. While Mail is closed, navigate to your user Library folder and drag the Mail folder to the Desktop. Reopen Mail. If Mail successfully opens, either your mail messages or your mail folder settings are corrupt. Unfortunately, the “quick fix” for this problem is to no longer use your mail folders (i.e. delete your mail). Most people do not want to lose their mail, and if your mail server does not keep copies of your messages on it, deleting these folder means you rebuild your mail accounts from scratch. Luckily, Apple’s Mail does have an easy way to rebuild messages and folders, so if you want to try this, read the article on Importing and Rebuilding Mail.

Did this guide work for you? How else have you been able to get your Mail.app to open when it otherwise wouldn’t? Let other readers know in the comments.

 

 

 

 

 

 

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Working with Unknown File Extensions in Mac OS X

by Matt on December 21, 2011

Two days ago, I posted an article that teaches you how to open a file that is unknown to use in Mac OS X. It describes how Mac OS X tries to figure out what kind of file you have, as well as how to use the Mac App Store to find applications that can open your file. What happens, though, if you still can’t read open your file after reading that article? Well, if your file has an extension (the “suffix” portion of a file name: the “.csc” in “My Special File.csc”), then there are some other sleuthing methods you can use to figure out what kind of file it is. Here are two good websites to start with:

  • FileInfo (www.fileinfo.com): This site has a very large database of extensions. You can search by extension or browse by file type. The search results will describe the type of file and associated applications. What is nice about this site is that many file types include Mac applications, whereas most other sites include only Windows applications. Note: If a file extension page does not list any compatible Mac applications, that does not preclude such a possibility. It simply means the web site does not know if there are compatible applications.
  • File-Extensions (www.file-extensions.org): This site is very similar to FileInfo, but there are two noteworthy differences. First, the file extension descriptions generally do not list Mac applications. Second, it is common for file extensions to have not only more than one application associated with it but also more than one type of file associated with. For example, while .asc is typically an ASCII text file that any old text editor can open, it can also be a 3D Studio Max scene file, which means that it could be a configuration file for a 3D movie renderer. Obviously, those are very different types of files. File-Extensions does a much better job than FileInfo of showing you all the possible file types – not just the most common ones.

Once you have used one of these resources to determine what kind of file you have, you will have to figure out which software can read the file. If FileInfo indicated that a Mac OS X application will open the file, and you already have that application, then you can try opening the file with that software. Otherwise, here are some further troubleshooting steps:

  1. If you have already been able to determine which Mac OS X software you need, then you simply need to acquire the software. If it is commercial software, you will need to purchase it online or in a store. You might, however, visit the software manufacturer’s website to see if it offers a free demo version of the software. This will allow you to verify whether the software can really open your file. You could also visit AlternativeTo to see if there is a more cost-effective solution.
  2. If the software is freeware/shareware, you likely can use MacUpdate or Version Tracker to find the software or do a Google search to find the author’s website.
  3. If you do not wish to purchase expensive software, or if FileInfo indicated any number of applications may be able to read the file, then it may be worth doing a Google search to see what other Mac users are doing to open these files. For example, if you’re trying to open a QIF file, you might search for “Mac OS X open QIF files.” You can visit Apple’s Discussions forums and search there, as well. If you want even more accurate information, read MacRumors’ discussion forums.
  4. If neither FileInfo nor File-Extensions indicate there is a Mac-compatible application for the file, you should do a Google search, as well. Some files simply cannot be opened (or done so without much effort). For example, if you receive a Microsoft Publisher file (which may have a .pub extension), there is currently no Mac application that can read the file. You might still run a search, such as “Mac OS X how to open Microsoft Publisher files.” If the end result is that you will need to open the file in Publisher on Windows, at least you will know.

Did these tips work for you? How else have you uncovered the secrets of a file extension? How were you then able to open your files? Let others know in the comments.

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How to Open an Unknown File in Mac OS X

by Matt on December 19, 2011

When you double click a file in Mac OS X, Finder tells you that there is no default application specified to open the file. When this happens, Finder does not open the file unless you tell it which application can read the file. How do you determine whether you have an application that can read the file, and which is the best one for it? Well, there are several reasons Finder may not know how to read a file, and you may need to use trial and error to determine which reason is plaguing your particular file. The four most common problems are:

  • You truly do not have any software that can read the file.
  • You have software that can read the file, but the file is corrupt, and therefore, cannot be opened.
  • You have software that can read the file, but the Finder cannot determine what kind of file it is, and therefore, does not associate any application with it.
  • You have software that can read the file, but the software does not tell the Finder that it can read the file, so you must manually open the file from within the software.

Finder does not know what to do with this file, but if you select “Choose Application,” you can tell Finder which application should open the file.

While you certainly can open each application on your computer and then see if the application can read the file, it is likely to be faster if you try to determine what type of file you have. You can then determine if you have the appropriate software to open it, and if not, which software you will need.

One of the easiest ways to find an application to open your file is to search the App Store, at least if you are using the latest version of Snow Leopard or Lion. When developers submit applications to the App Store, they can specify types of files their applications can open, and they have two ways to do that: tell Apple which file extensions an application opens, or which UTIs (uniform type identifiers) to associate with an application.

Let’s say you wanted to open a PDF, but you didn’t have an application to do it. There are two ways you can ask the App Store to search for an application that opens your file. First, if you have tried opening the file but get the error message in the above image, you can press “Search App Store.” Second, you can click on the file in the Finder, go to the File menu, and select Open With –> App Store. Either way, the App Store application opens and begins searching.

Here’s the tricky part: if the Finder can identify a file’s UTI in the file’s metadata, the App Store searches by metadata. This is the preferred method. If it can’t determine the UTI, it searches by file extension, if there is one. The problem with searching by file extension is that some applications’ files share the same extensions, even though the files are very different. For example, most PDF files on a Mac are Adobe Acrobat files. They can be, however, Netware printer definition files, Ed-Scan graphic files, or several others. An Acrobat PDF’s UTI should always be com.adobe.pdf, so there’s little risk the App Store will show you applications that cannot open the file.

Finding Files’ UTI Metadata

If your file is in working order and Spotlight has scanned it, you may be able to find its UTI from the Terminal. Open Terminal and type: “mdls /path/to/yourfile” (without the quotes). Terminal will spit out quite a bit of information about your file. Scroll back up until you see the line marked “kMDItemContentType.” The file’s UTI is the value associated with this variable.

Searching the App Store by File Extension or UTI

If you want to quickly find applications in the App Store that can open a specific file extension or UTI, you can specify this in your search. To search by file extension, simply type, “extension:” (without the quotes) followed by the extension characters. For example, to search by the extension .PDF, type: extension:pdf. To search by UTI, type, “uti:” (without the quotes) followed by the UTI string. For example, to search for the UTI com.adobe.pdf, type: uti:com.adobe.pdf.

If you still cannot figure out what kind of file you have or which applications can open your file, there are several ways to investigate. It’s generally easier if your file has an extension, but even if it does not, this guide can point you in the right direction.

Caution! By completing the following troubleshooting steps, there is a small chance that your file will become unreadable by its proper application. This is because some applications change data in the file without asking you, and if the wrong application is the one changing the data, your file may become corrupt. Therefore, you should duplicate the file in question and work off of the copied file. That way, you still have the original, untouched file if things go awry. (You can duplicate a file by selecting it in the Finder and choosing Duplicate from the Finder’s File menu.)

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A Guide to Startup Key Combinations in Mac OS X

by Matt on December 17, 2011

Your Mac has many secret abilities when you first turn your computer on, and you may have already discovered one or two of these, especially if you’ve ever had to troubleshoot startup problems. This article is a simple list of the startup commands I’ve used over the years. Hopefully it will serve as a quick guide for you. To perform a startup key combination, you simply hold down the keyboard key(s) corresponding to the appropriate purpose when you turn on your Mac. In an ideal world, you hold the keys down while pressing the power button, but some tricky combinations likely require you to press the power button and then very quickly hold down the keys on the keyboard (before the startup sound finishes playing). As you already know, the normal boot sequence is: black screen –> gray screen –> gray screen with Apple logo –> gray screen with Apple logo and spinning gear –> desktop. You should continue holding down these keys until either the gray screen switches to something other than the Apple logo, or if your command needs to boot the computer, hold them down until the Apple logo appears with the spinning gear. Lastly, remember that resetting PRAM/NVRAM will restart your computer, so once your computer reboots while you hold down the Command-Option-P-R keys, you can let go. Hope this helps!

 

 

 

 

 

 

 

 

Key Combinations for Booting from Various Disks

Key Combination Purpose
C Start up from a bootable CD/DVD (in the drive)
N Boot from a NetBoot server
Command-R Boot from Recovery Petition (Lion only)
Option Start the Startup Manager, which lets you choose to boot from any bootable source
Delete-Option-Command-Shift (DOCS) Skip booting from the default boot disk and instead look for any other available boot disk

Key Combinations for Troubleshooting Hardware Problems

Key Combination Purpose
D Intel Macs: Boot from the Apple Hardware Test partition on the appropriate DVD (PowerPC users must hold down “Option” and boot to the Startup Manager to run the Apple Hardware Test)
Command-Option-P-R Resets the NVRAM/PRAM
Command-Option-O-F PowerPC Macs: Boot to Open Firmware (command line)

Key Combinations for Troubleshooting Operating System Problems

Key Combination Purpose
Shift Mac OS X starts in “safe” mode
Command-S Mac OS X starts in “single-user” mode
Command-V Mac OS X starts in “verbose” mode

Miscellaneous Key Combinations

Key Combination Purpose
T Put the Mac into “target disk mode,” which allows other Macs to access your internal hard drives via FireWire or Thunderbolt
6-4 Allows compatible Macs to boot with the 64-bit kernel if they normally boot from the 32-bit kernel (Snow Leopard only)
Eject/F12/mouse or trackpad button held down Eject a CD/DVD currently in the drive

Are there any key commands missing from this list? What tricks do you have at startup? Let others know in the comments.

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Manually Managing MTU Size in Mac OS X

by Matt on December 15, 2011

MTU stands for “Maximum Transmission Unit.” Whenever you transmit and receive data in Mac OS X, the data is broken up into smaller pieces (called packets) and then reassembled on the other end of the connection. Think of it like a jigsaw puzzle: You go to the store to find a puzzle, and they come in different sizes, ranging from 20-10,000 pieces. Everyone knows that the more pieces you need to put the picture back together, the longer it takes. The same thing is true with computer data. When you want to download a song from the iTunes Music Store, you want it to get it as quickly as possible, and as you increase the amount of data in a packet, you decrease the number of packets iTunes needs to transmit, which reduces the time it takes to receive the file. That’s great until you tell the computer to transmit packets larger than your ISP can handle. If your ISP can handle 1500 bytes, but you specify 1800 bytes, you might get the 1500 bytes, but then your computer has to tell iTunes, “Hey, I didn’t get those other 300 bytes. Please resend them.” iTunes sends the data, but it has to do so in a new packet, which means it takes longer to get all the data to your computer.

Determining the MTU for your current network is not difficult, but it is a matter of trial and error. There are some caveats. First, each network has its own MTU, so your home network may be different from work and from the local coffee shop. Thus, if you set a custom MTU and then change networks, you probably need to change the MTU to match the new network. Second, the standard MTU size for Ethernet/AirPort connections is 1500. For Ethernet DSL (PPPoE), it is 1492. Third, it is unlikely your MTU size is greater than 1500 or lower than 1400, but feel free to experiment with different values.

When you want to be able to manually set your MTU size, you must first open System Preferences, then the Network system preference. When that preference opens, select the network interface you use to connect to the Internet (likely Ethernet or Wi-Fi), and then press the “Advanced” button in the lower right corner of the window. When the Advanced window appears, you can then click on the “Hardware” tab (or the “Ethernet” tab if you’re running Snow Leopard or earlier). This is the section where you can edit the MTU value. Mac OS X can already determine your network’s proper MTU, so only adjust this setting if you are experiencing persistent slowdowns, especially when attempting to download files. Read on to determine your ideal MTU value.

Mac OS X can already determine your network’s proper MTU, so only adjust this setting if you are experiencing persistent slowdowns, especially when attempting to download files.

 

To determine your network’s MTU:

1. Open Terminal (in your Utilities folder). You are going to “ping” another server. This means you are going to send another server a little bit of data and ask it to respond to you. It is the equivalent of tapping someone on the shoulder, except in this metaphor, you get no response when you tap someone too hard (or send a packet that is too large).

2. Type this command and press Return:

ping -c 2 -D -s 1472 example.com

The -c switch tells ping how many packets to send. I chose to specify two packets. You could choose 1 or 100 or even eliminate this switch to ping endlessly (not recommended, but if you do this and need to stop the ping, hold down the Control key and press the letter “C”).

The -D switch tells ping not to fragment the packet (meaning that if the size of the packet is too large, don’t send it at all).

The -s switch allows you to specify the size of the packet in bytes. That is what the 1472 next to the -s switch. This is important: Any ping that you do via the above method adds 28 bytes of overhead to the ping. This means you must add 28 bytes to the size of your packet to get the packet’s true size. In the above example, we pinged example.com with 1472 bytes. Add 28 to that number, and you get 1500. If 1472 is the largest packet you can successfully send, then your MTU value is 1500. If the largest packet you could send were 1464, then your packet size would be 1492.

3. When you run the above command, ping can give you two different replies:

ping: sendto: Message too long

If you get a response that the message is too long, that means the packet size is too large and must be reduced.

1480 bytes from 208.77.188.166: icmp_seq=0 ttl=46 time=185.42 ms

The above line is the other reply you may receive from ping, and it indicates a successful ping. Your response may look slightly different: the IP address may change, the time it takes to ping may change, etc. The point is that this line looks very different from the “message too long” line. If you ran the exact command from above, you should see either two successful pings or two failed pings, since the -c switch was set to 2. In fact, at the end of the ping process, you may see a statistics line that shows either 0% packet loss or 100% packet loss (0% means every packet went through, 100% means none of the packets did).

4. Your goal is to continually increase the packet size in the ping request until you receive a “message too long” reply (or, if you are only receiving those messages, lower it until you can successfully ping a server). Add 28 to the largest packet size you can successfully ping, and this is your MTU. To manually set your MTU in the “Hardware” tab of the Advanced window in the Network system preference, change the “Configure” pop-up menu form “Automatically” to “Manually.” Then, switch the “MTU” pop-up menu from “Standard” to “Custom.” Finally, enter your MTU in the box that appears and click OK to save your settings.

Did this guide work for you? How important do you feel it is to edit the MTU value? How has it affected your network performance? Let others know in the comments.

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How to Import and Rebuild Your Email in Mac OS X

December 13, 2011

Apple’s Mail can import folders and messages from many other email applications. This is obviously useful if you are switching from another email program and have not stored your messages on the email server. The import service provides a unique troubleshooting tool, however, in that you can use it to re-import your existing mail folders. [...]

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Where to Find and Download Hardware Drivers for Mac OS X

December 11, 2011

You have just purchased new hardware to work with your Mac. It could be something as simple as a mouse or as complex as a FireWire, rack-mounted audio interface. The most popular additions, though, are printers (and all-in-one, multifunction devices), scanners, and input devices like mice, keyboards, and tablets. Some of these devices seem to [...]

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