Why does the user name get rejected when some users log in to Exchange Server 2007 via POP3?

Question:- Why does the user name get rejected when some users log in to Exchange Server 2007 via POP3?

Answer:- We're all familiar with the user principal name (UPN); it includes a user's log-on name, the @ symbol, followed by the domain name. Errors can occur when users have a UPN that exceeds 40 characters, which is the default limit for POP3 set by the MaxCommandSize setting. You can resolve this issue in one of two ways. The first method just increases the value of MaxCommandSize, this way:

• Start the Exchange Management Shell.
• Type Get-POPSettings to view current settings. You'll notice the default value is 40.
• To increase the value to 50 (the upper limit is 1,024 bytes), type Set-POPSettings -MaxCommandSize 50
• Restart POP3 for the changes to take effect.

2. The second method increases the value of MSExchPopImapCommandSize via the Adsiedit.msc snap-in. It's a bit more complicated...

Via:mcpmag.com