Previously I discussed the various email protocols which support the sending and receiving of emails. One those protocols is the Post Office Protocol version3 (POP3) protocol. In this article I will discuss some of the potential POP errors you may receive when using POP3 clients, such as Microsoft Outlook, and email servers such as Microsoft Exchange.

Remember that the Post Office Protocol version 3 (POP3) allows email client software such as Outlook and Outlook Express to retrieve email from a remote server.  The Outlook client accesses only its own server inbox and cannot access other inboxes on the server nor can it read public or private folders also on the server. POP3 is not intended to provide full manipulation of e-mail on the server.

Email messages are usually downloaded and then deleted from the server. But there is an option to leave temporary copies of the emails on the server and have them removed after a certain amount of time has expired. Once the emails are downloaded the user can take actions against those messages without needing to be connected to the server. After syncing back up with the server, email can then be sent using Simple Mail Transfer Protocol (SMTP). The email server functions like a U.S. Post Office. It is a temporary storage area until email reaches its final destination – another POP3 client.

Well, one of the errors you may encounter is when a POP3 Connector is unable to download email. The error occurs while processing the RETR command.

An example of this is using Microsoft Exchange Connector for POP3 Mailboxes to download email from individual mailboxes or from Internet Service Provider (ISP) Post Office Protocol Version 3 (POP3) mailboxes. The POP3 Connector download fails and is unable to retrieve messages. As an administrator you should review the application log for error messages. You should expect to see error messages such as:

Event ID 12050
Source: POP3Connector
“POP3: Failed to check the POP3 account for <mailbox> at host POP3.POP3Server.com on port 110. The error is 10060″ (It may also say “The error is 1232”.)

Event ID 12058
Source: POP3Connector
“POP3: There was an error processing the RETR command. The Error is 10060″
(It may also say “The Error is 1232″.)

The error messages that you see are likely caused by emails in the mailbox of the POP3 server that contain the Null character. POP3 Connector for Small Business Server 4.5 cannot download emails which contain Null characters.

The solution is to remove those email messages that contain the Null character(s) from the mailbox of the POP3 server. Once this is complete then the POP3 Connector will be able to download the remaining email messages assuming those emails do not contain any Null characters.

There are a couple different options that allow you to cleanup the POP3 server mailbox. The first option is to use another mail client such as Microsoft Outlook or Outlook Express. The second option is to start a telnet session to connect to the server, download the messages and then delete any emails which contain Null characters.

There are other errors you may have when using POP3 and Outlook. One such error happens when you try to connect to a POP3 server from Outlook 2007 or earlier from a Windows Vista-based computer. When you try to make the connection you are prevented from completing the action. What you are finding is that Windows Vista did not include a needed file called Msnsspc.dll. This file is needed to access MSN accounts. They might be MSN mail accounts or MSN Hotmail or even Microsoft Windows Live Mail accounts which use the POP3 protocol.

The Msnspc.dll file is needed for authentication to MSN accounts and is required to support POP3 connections. Without this file, Windows Vista users are unable to access their email using the POP3 protocol.

To fix this problem there are two options. The first option is to download the Microsoft Office Outlook Connector which will provide access to MSN accounts. You can retrieve this code from the Microsoft download web site.

Your second option is to modify the MSN POP3 account settings. After starting Outlook, open up the Tool menu and click on Email Accounts. Next click “view or change existing email accounts”. Find and verify the account you wish to change. Make sure that the Incoming mail server (POP3) field is set to “pop3.live.com” and that the Outgoing mail server (SMTP) field is set to “smtp.live.com”.

You’ll also need to check that the “My Server Requires Authentication” and “Use Same Settings as My Incoming Mail Server” are selected on the Outgoing Server tab. Finally, verify that both boxes indicate that SSL is to be used and that the incoming mail port is set to 995. Also verify that the outgoing mail port is set to 25. Click next or hit enter and you are finished. That’s it.