It's quite common for companies to disable user accounts in Active Directory, rather than delete them, when a user leaves the company.This allows other IT staff and managers to access that user's data and email after they are gone.
Lync Server 2010 uses several methods of authentication: Kerberos, NTLM, and certificate based.
Kerberos is the default authentication method and successful authentication results in the client receiving a Kerberos ticket that's good for 10 hours.
Kerberos is used when users are accessing Lync Server while on the domain.
NTLM is used for authentication from other locations, such as the Internet for remote access using Lync Edge servers.
To configure Outlook to only send or only receive messages, do the following: When you disable the send operation, Outlook will still let users create an email.
Then, when they initiate the send and receive operation, Outlook will move the message from the Outbox to the Sent folder, but it won't actually send the message.
This behavior is seen even though we check the option to “Filter out disabled users” while creating the Sync Connection.
Note : The behavior is continued to be seen even when a Custom Filter is defined in LDAP syntax in the box provided .
Nor will it alert the user to that fact, so use this option carefully.
Users could think they're sending email when they're not.
Read further to get more details on the issue & the workarounds .