Would the Disk bottleneck affect the mail flow?

As well all know, yes that will “affect the slow or affect” the mail flow

Reason:

Every message that is received by an SMTP gateway is saved to a disk.

• With a default message size of 50 KB, about 7 to 8 disk writes occur for each message processed by the SMTP gateway.
• This behavior is expected. Generally, SMTP performs 7 disk writes for every message queued that is smaller than 32 KB.
• An SMTP gateway’s write buffer is 32 KB. Therefore, messages that are larger than 32 KB require an additional disk write for every 32 KB.

For example, a 100-KB message requires 10 disk writes to save the message in the queue.than 1 GB of memory.

it is good to run EXTRA to check the disk bottleneck and blame the “Third party” with a proof J

I’ve recently come across a problem where, For Exchange 2003 and 2007 co-existence environment, When an mail-enabled object is created, the x:400 address will not be stamped.

This would result in an NDR’s with the recipient name “BsB57FD40C9308F7479BF159E9F227E5DD_

cn=E5D7F3DC762455418BB3D96C1B7C13BC@domain.edu”

Reason:

This would happen because of mission X:400 address

Fix:

• The Exchange 2003 RUS is responsible to update the object attributes in a co-exist Environment.

• The Recipient Update Service has three System Policies that are installed by default when you install Exchange 2003. They are “Mail Enable Recipient”, “Mailbox Enable User” and “Hidden DL membership”.

• If the recipient update service identifies than a new entry was added (or modified), and it does have the mailNickname to be considered mail-enabled.  Therefore, by default, the purportedsearch attribute should be below:

(|(&(objectCategory=person)(objectClass=user)(mailnickname=*)

(targetAddress=*))(&(objectCategory=person)(objectClass=contact)

(mailnickname=*)(targetAddress=*))(&(objectCategory=group)

(mailnickname=*))(&(objectCategory=publicFolder)(mailnickname=*)))

• You can locate the “Mail Enable Recipient” object by using Adsiedit.msc tool:

CN=Mail Enable Recipient, CN=System Policies, CN=ORG_NAME, CN=Microsoft Exchange, CN=Services, CN=Configuration, DC=DOMAIN_NAME,DC=com

• The user, contact and public folder object which have mailnickname and targetaddress (not for public folder) attributes.