Solved

Exchange 2013 MBX / CAS incoming email

Posted on 2013-12-05
2
655 Views
Last Modified: 2013-12-10
quick overview of Email Server configuration:

Message Labs 3rd party spam filter scans and sends email through

VMware Virtualized on a blade server cluster connected to dedicated iSCSI storage.

All vmware drives are thick provisioned

2 CAS Servers Load balanced ~ 100gb C: (40% full)
2 MBX Servers with a DAG.  100gb C:  (50% full)  2TB D: (10% full) for mailbox databases and 500gb E: for transaction logs.   Logs get cleared after successful exchange aware backup.

My Question is this.

Backups started but ended up filling the C: on the mailbox database servers which obviously caused those MDB servers to stop working.   Since the CAS servers were still up and running, would inbound email queue up at the CAS Servers being unable to deliver it at all to a database server (i know its supposed to act simply as a proxy) or would it try to deliver them knowing the recipient does exist and hence the email is lost?  or would the end user get a bounce back, undeliverable?   Ive got a decent understanding of how the mail flow inbound works but just curious about this specific instance.   I had a 3 hour window,  just under 1 during normal business hours.
0
Comment
Question by:DeltaMN
2 Comments
 
LVL 63

Accepted Solution

by:
Simon Butler (Sembee) earned 400 total points
ID: 39698867
Mail should queue. At worst case scenario at Message Labs (as the hub transport rejects it). You shouldn't lose any email. This is just the same as the databases dismounting.

Really simple to test for yourself - create a new database, then create a new user.
Dismount the database and attempt to send an email via Telnet to the new user. You should see the message be delivered, then run get-queue and you will see the message listed.

Simon.
0
 
LVL 53

Expert Comment

by:Will Szymkowski
ID: 39698965
In Exchange 2013 Shadow Redundancy is the place where the mail items will queue before the mail item/s actually reaches the speified mailbox. This process is on the Mailbox server and has no bearing on the CAS role (as you stated CAS is basically a glorified Proxy which is stateless).

Shadow Redundancy is enabled by default unless otherwise disabled from Powershell.  Also as you have stated this will also be available on the second DAG member. The queues will hold on to the messages until they expire base on the number of days you specify.

Will.
0

Featured Post

Live: Real-Time Solutions, Start Here

Receive instant 1:1 support from technology experts, using our real-time conversation and whiteboard interface. Your first 5 minutes are always free.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Follow this checklist to learn more about the 15 things you should never include in an email signature from personal quotes, animated gifs and out-of-date marketing content.
MS Outlook is a world-class email client application that is mainly used for e-communication globally.  In this article, we will discuss the basic idea about MS Outlook, its advanced features, and types of MS Outlook File formats.
To add imagery to an HTML email signature, you have two options available to you. You can either add a logo/image by embedding it directly into the signature or hosting it externally and linking to it. The vast majority of email clients display l…
A short tutorial showing how to set up an email signature in Outlook on the Web (previously known as OWA). For free email signatures designs, visit https://www.mail-signatures.com/articles/signature-templates/?sts=6651 If you want to manage em…

808 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question