There are 2 types of mail volume that we track, Logical and Physical, how is this mail volume counted?
For Mailbox Activity, we track two volumes. 1. Physical Messages, which does not consider the number and relative location of recipients, but is really just concerned with the number of times the mailbox receives a message.
2. Logical Messages, which considers the number of recipients that the message is going to (all addresses in a Distribution List would be counted), with the exception of custom recipients. MessageStats is not performing any work on the recipients, like Distribution List Expansion.
Logical Messages are further broken down by Internal and External Messages. This is the relative count of each direct recipient (i.e. Distribution Lists are counted as a Single Internal Recipient) and their relative location to the organization. For custom recipients, a lookup of the accounts is performed using the MessageStats database. The SMTP Address of Custom Recipients is substituted with the address. NOTE: Support for Custom Recipients was added in 5.0.
For 4.3, all Custom Recipients are marked as Internal Messages. Below are sample results from MessageStats 5.0+ and 4.3. when a new mail message has the following recipients and is 50756 bytes in size:
Mailbox Fred - A mailbox that is on the same server as the originator Mailbox John - A mailbox that is on another server in the organization Custom Recipient Harold - A custom recipient that resolves to the address Harold@hotmail.com Some.User@SomeDomain.com - An external email address Distribution List Halifax - A mail enabled group that contains 8 mailboxes in the Organization.
MessageStats 4.3 would report the following results for submitted messages: