Is there a Maximum Length for userPrincipalName in Active Directory?

Question

I am writing an application that is linked to Active Directory, and I need to store the userPrincipalName in a database table, but I do not know how big the field would need to be.

On MSDN, no Length is given, and neither in RFC 822. Now, before I revert to the DOMAIN\Username that has a defined Length (sAMAccountName is less than 20 chars, NETBIOS Domain Name is max. 15 chars), I wonder if anyone knows what the limit is either by standard, or by the implementation within both Windows 2003 and Windows 2008 domains.

Answer 1

On Win2k3 SP2 the longest userPrincipleName it allows me to create is 1013 characters long.