SBS 2008 exchange fault tolerance

Discussion in 'Windows Small Business Server' started by TimA, Dec 16, 2008.

  1. TimA

    TimA Guest

    I am trying to figure out a way that I can have fault tolerance for incoming
    email when the server is in maintenance (rebooting/offline).

    I was hoping that when the server is offline email will queue somwhere
    (whether it be a provider or on another SBS server I have of a different

    I looked at 'smart host' but that seemed to be something that is for servers
    with dynamic ips or for sbs networks that are on ISPs that dont allow for
    port 25.

    If I have 2 SBS servers (for different domains) can I have the MX records
    for domain #1 to point to both servers.

    If I do this when server #1 is down, will email go to server #2. Also when
    server #1 comes up will all the mail queues on server 2 then get delivered?
    TimA, Dec 16, 2008
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  2. Hi Tim -

    Many ISPs will offer secondary MX services that will allow email to queue
    until your server comes back online. When the secondary MX sees your server
    online, it will dequeue messages and deliver to your server.

    If you're just worred about normal maintenance (the occasional reboot,
    patching, etc.) - you don't necessary have a big worry, since most mail
    servers will retry delivery for up to 48 hours before actually failing the

    If you want to go one step further, we use Reflexion for a hosted email
    security & archiving solution. Our MX record points to Reflexion - since
    we're using them for both email security & archiving, all inbound messages
    are scanned for viri, any spam is quarantined, etc. and all legitimate
    emails are archived before being delivered to our Exchange server. The nice
    part about this is that with the archiving, there is a web interface to
    access and search the archive - and in the case of a true disaster where our
    Exchange was offline, we can read & send email from within the Reflexion
    archiving interface. There is even an application that installs on your
    Exchange server so that internal only emails are archived as well, and it
    will sync your contacts - so if you need to work from the Reflexion archive
    interface, your contacts are there as well . . . There are other similar
    solutions available as well.
    Chad A. Gross, Dec 16, 2008
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  3. For normal reboot/maintenance issues, you don't need to do anything. The
    SMTP protocol allows for temporary server downtimes and will automatically
    re-try later. But if you want an additional layer of protection, look into a
    secondary MX record. Your ISP may offer one, or someone like Exchange
    Defender (good spam removal as well) will give you access to your email even
    while you're down. And many DNS providers, such as ZoneEdit, offer backup MX
    holding for a very reasonable price. Personally, I ask my ISP to do as
    little as possible except stay out of my way. But I use ZoneEdit BackupMX
    and OwnWebNows ExchangeDefender.
    Charlie Russel - MVP, Dec 16, 2008
  4. "Personally, I ask my ISP to do as little as possible except stay out of my
    way", same here.

    smarthosts are for sending mail, secondary MX (or the absence of and just
    relying on retries) are for receipt.
    SuperGumby [SBS MVP], Dec 16, 2008
  5. TimA

    Leythos Guest

    Dynamic DNS has a MXBackup solution that stores your email at their site
    until your server is back online and requests it.
    Leythos, Dec 17, 2008
  6. Why am I not surprised that you agree with me about ISPs.<G>
    Charlie Russel - MVP, Dec 17, 2008
  7. Don't even have a router here - pure DSL modem, connected to one of my WAN
    ports on the Xincom 502. (Other is connected to the Cable modem. )
    Charlie Russel - MVP, Dec 17, 2008
  8. TimA

    Chad A Gross Guest

    No, we're running our email completely in-house on our Exchange server.
    We're using a hosted email security service (Reflexion) that scans all
    inbound/outbound email for malware / spam and automatically archives all of
    our email as well. But it does that in the cloud as messages are being
    relayed to our Exchange server.

    Personally, I think a second Exchange server in an SBS environment in most
    scenarios is overkill . . .
    Chad A Gross, Dec 18, 2008
  9. TimA

    Chad A Gross Guest

    No POP3 connection. Reflexion delivers all inbound emails to our Exchange
    server via normal SMTP. It just scans, filters & archives those messages
    before delivering them to our Exchange server.

    There is some administrative overhead with setting up users with Reflexion,
    but honestly not much. There's two pieces to Reflexion - Reflexion Total
    Control is their core mail security service (virus scanning, anti-spam,
    quarantines, etc.). The second piece is RADAR - their archiving piece.

    With Reflexion Total Control (the security piece) - we pay per mailbox per
    month. Reflexion Total Control can be configured to automatically add new
    users on their first outbound message. Since we use Reflexion as a
    smarthost for our Exchange server, they see all outbound messages. This
    way, if I add a new user and forget to add them to Reflexion Total Control,
    the first time the user sends an email externally, Reflexion will
    automatically add them as a new user in Reflexion Total Control and email
    the user the welcome email with their logon information etc.

    RADAR works a little differently - we pay per GB of storage space used each
    month. As a result, we have more control over what mailboxes get archived.
    There is software that gets installed on the Exchange server that
    facilitates the administration of RADAR - this not only allows us to control
    what mailboxes are getting archived, but it also works with Exchange
    journaling to upload local-only emails to the RADAR archive. One of the
    nice features with RADAR is that it uses single-instance storage in your
    archive - not only for attachments but also for messages themselves.

    So to answer your question - when I have a new user, I add them to Reflexion
    Total Control, then on my server I log in to the ExchangeSync application
    and enable archiving for their mailbox.
    Chad A Gross, Dec 18, 2008
  10. Pop3 is inbound and picks up the email

    Smarthost is outbound to the ISP

    Not the same at all.
    Susan Bradley, Dec 19, 2008
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