Emails "stuck" in categorizer

[TravTrav]

Hello All, here is my issue:

I have several groups that when people are trying to send emails to them, they dont get through. When I track the messages, they only get as far as "SMTP:Message submitted to Categorizer" and then there is no other information. This only happens when they are trying to email to these groups, and if there are individuals being sent to as well, the individuals get it, but no one in the groups. Any ideas?

 

[TravTrav]

No one?

 

[xmsre]

Look in the application log and see if you have any retryable errors. Also use perfmon to see how many categorizations per second you are getting. Also look at ldap operations.

Many times, it comes down to inappropriately applied restrictions. The categorizer expands the message envelope and does an ldap lookup for each recipient. If you send a message to a group containing 2000 users, that's 2000 lookups. Now let's ay you have a group containing 100 users that is placed on the restrictions of every mailbox in your environment. Now the categorizer does 2000 lookups, then for each member of the group sent to it looks at the restrictions on the mailbox, expanding the 100 member group and doing an additional 100 ldap lookups. In this case, instead of 2000 ldap lookups, it's 200,000 ldap lookups. You'll have messages bouncing around the categorizers for hours andd see a series of retryable errors in the application log.