Consider the following scenario. You use either Microsoft Outlook Express 6.0 or Microsoft Office Outlook 2003 to reply to an e-mail message that was received by using a POP3 e-mail account. When you click Reply to reply to the POP3 e-mail message, the e-mail address or the display name of the person to whom you are replying is incorrect.
This problem may occur if all the following conditions are true:
Your mailbox is located on a server that is running Microsoft Exchange Server.
The sender's display name is encoded by using UTF-8.
The sender's display name contains both of the following:
One or more extended characters, such as à, á, â, ã, ä, or å
Either of the following updates was applied to the Exchange server that contains your mailbox:
Microsoft Exchange Server 2003 Service Pack 1 (SP1). For more information about Exchange Server 2003 SP1, click the following article number to view the article in the Microsoft Knowledge Base:
836993 How to obtain the latest service packs for Exchange Server 2003
Microsoft Exchange 2000 Server Post-Service Pack 3 Update Rollup. For more information about Exchange 2000 Server Post-Service Pack 3 Update Rollup, click the following article number to view the article in the Microsoft Knowledge Base:
870540 Availability of the August 2004 Exchange 2000 Server Post-Service Pack 3 Update Rollup
To resolve this problem, use one of the following methods, depending on your situation.
Method 1: Install Microsoft Windows XP Service Pack 2 (SP2)
For more information about how to obtain Windows XP SP2, click the following article number to view the article in the Microsoft Knowledge Base:
322389 How to obtain the latest Windows XP service pack
Method 2: Install the MS04-018 cumulative security update for Outlook Express
For more information about the cumulative security update for Outlook Express, click the following article number to view the article in the Microsoft Knowledge Base:
823353 MS04-018: Cumulative security update for Outlook Express
After you install this cumulative security update, follow these steps to set the
registry subkey and to enable the hotfix:
Quit Outlook Express.
Click Start, click Run, type regedit, and then click OK.
Locate and then click to select one of the following registry subkeys:
If these registry subkeys do not exist, create them.
After you select one of the subkeys that are specified in step 3, point to New on the Edit menu, and then click DWORD Value.
Type Q834511, and then press ENTER.
Right-click Q834511, and then click Modify.
In the Value data box, type 1, and then click OK.
On the File menu, click Exit to quit Registry Editor.
To work around this problem, do not use a comma or an extended character in a display name.
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
Outlook Express 6.0 and Outlook 2003 use the Inetcomm.dll file to parse message headers that are received by using a POP3 e-mail account. When the display name contains only a comma and does not contain an extended character, the display name for the From field is enclosed in quotation marks. When the display name contains both a comma and an extended character, the From field looks similar to the following example:
When Outlook Express parses the From field, it considers the comma as a separator if the string is not enclosed in quotation marks.
If you send a message when the conditions that are listed in the "Cause" section are true, more than one message may be sent. In this scenario, one message contains the correct and complete SMTP e-mail address. The other message contains an incorrect or incomplete SMTP e-mail address. If a recipient receives the message that contains an incorrect or incomplete SMTP e-mail address, the recipient cannot reply to the message.