E-mail can be sent in either plain text or HTML-formatted. So what exactly does that mean? Well, originally, e-mail was based on just straight text. What you typed was what you saw. With the new HTML-formatted e-mails, you can include pictures, hyperlinks, and other web page characteristics in your e-mails. It's almost like composing a web page within an e-mail message. Unfortunately, if the person you are sending an HTML-formatted message to is using an e-mail program that doesn't support HTML, they'll get a message with a lot of HTML tags (, , , etc.) scattered throughout the text. The good news is that most e-mail programs default to the plain text format as long as you don't include any pictures, or other HTML elements.

To check your e-mail program's settings, check the Options or Preferences and look for the "Formatting" section. This should tell you how your outgoing messages are being formatted. If there is no such option, you can be pretty sure that you're only sending plain text messages.

The file was most likely encoded in a MIME format, which needs to be decoded before you can open it. This is typical of attachments sent through AOL. To decode a .mim file, use WinZip (if you don't already have it, get it at Download.com. From the File menu of WinZip, select "Open Archive." This should open the MIME file and list of all its contents. You can then use "View" button to see the file, or use "Extract" to save the file.

The most likely reason you can't send the file is because it's larger than the disk quota your ISP allows you to have. The disk quota is how much space your e-mail account is allowed to use up. When you send a file, it must be under that amount or it won't get sent.

If you are attempting to send just a picture, and it won't go through, that means the image file is probably very high-resolution and un-compressed. Most images are not more than a couple hundred Kilobytes at the most (1024 KB in 1 MB). If you convert it to JPEG (.jpg) format, it should be easily small enough to send. If you don't have a image-editing program that can do this, you can most likely find one at Download.com. Just enter "JPEG" or "image-converter" in the search box and you should find a good program that you can download and use to compress your image files.

Most e-mail programs will let you attach more than one file at a time to a single message. Just click the "attach file" icon and select the file from your hard drive. Then repeat the process to add another file. Keep in mind, many ISPs do not allow attachments over 2 or 3 Megabytes, so make sure the total of you attachments is not too large or the files may not get sent.

If you are sending your message through a Web-based e-mail interface, some Web-mail systems will allow you to attach multiple files, but others may not. If you can only attach one file, your only option is to send multiple e-mails with one file attached to each one.

With all the fuss over viruses and worms like Hybris, MTX, Matric, and ILOVEYOU (not to forget their predecessors Melissa and Pretty Park), you're probably too scared to open any email attachment. Hey, relax a little. Here are three rules to follow that will keep any Windows user safe:

1. Check the file name carefully! Pay particular attention to the file extension, the last three letters. If the file extension is .exe, .com, .bat, .pif, .scr, or .vbs, be extremely suspicious. Those extensions belong to programs and scripts that can carry a deadly virus. Before double-clicking any such file, be sure you know that it is virus-free. If the extension is .gif, .jpg, or .wav, you're OK. If the extension is .doc or .xls, the file is an Office document that may contain macros. Open it with care. Don't be fooled by multiple extensions--the ILOVEYOU virus, for example, is called LOVE-LETTER-FOR-YOU.TXT.vbs. The only extension that counts is the very last one, immediately following the final dot.

2. Always save attachments instead of opening them directly. From inside your mail program, right-click on the file icon and save it to a location on your hard disk (the desktop is a good temporary holding area, but be sure you move the saved file to a better location after you determine it's safe).

3. Scan the saved file for viruses before running it. Be sure your antivirus software is installed correctly and up to date.

Are you inadvertently sending unreadable email messages to friends and family? It can happen if you use Outlook Express, whose default message format is HTML. When you send an HTML message to someone whose mail software can't decipher the HTML codes, they see screen after screen of gibberish (or a file attachment), with your message buried in the mess. Fortunately, you can choose either of two fixes:

To send a single message in plain text format, compose the message first but don't send it. Pull down the Format menu and choose Plain Text. Then click the Send button.

To set Plain Text as your default message format, open Outlook Express, pull down the Tools menu, and click Options. Click the Send tab and select the Plain Text option under Mail Sending Format. Click OK to close the dialog box. That will take care of all future messages.

Sometimes you need to play Sherlock Holmes to find out how an email message came to you. This is especially true if you use several email addresses. If you want to change details of a subscription to a mailing list or newsletter, for example, you need to know which mailbox the message was addressed to, and that's not always obvious from the To: and From lines.

The solution? Look at the full message header to see details about the sender, the account to which the message is addressed, and names and IP addresses of computers and servers the message passed through on its way to you. Often, you can get important troubleshooting clues from the message headers.

If you use Outlook Express, you can view the headers for any message using these steps:

1. Open the message in its own window.

2. Choose File, Properties from the Outlook Express menu.

3. Click the Details tab.

Does Outlook Express keep trying to send and receive messages when you're not connected to the Internet? Or does it not check often enough? The default settings for this important activity usually need to be adjusted, depending on what type of Internet connection you have. To get started, open Outlook Express and choose Tools, Options. Then click the General tab and adjust the following settings in the Send/Receive Messages box:
If you have a DSL line or a cable modem and you leave your computer on at all times, tell Outlook Express you want to check for email more frequently than the default setting of every 30 minutes. Try adjusting the setting so it reads Check for new messages every 5 minutes.
If you use a dial-up connection and you want complete control over when Outlook sends and receives your email, clear the checkmarks from the boxes labeled Send and receive messages at startup and Check for new messages every nn minutes.