Issue | Reason | Resolution
Outlook 2007 can oftern run into issues downloading users’ offline address books. In Exchange 2007, the Offline Address Book (OAB) is published in two ways. For Outlook 2003 and older clients, it is published to public folders. For Outlook 2007 it is published to a web folder called OAB (i.e. companyserver.domainname.com/oab).
When sending/receiving for OAB (offline address book) in Outlook 2007, it can fail returning an ‘Object not found’ error.
There are a number of causes for this error, most commonly, not specifying the default OAB for the database in Exchange (in MS infinite wisdom, they did not make a default OAB get assigned automatically). Ultimately, it comes down to DNS and the Certificate.
Exchange Server 2007 utilizes a number of host names including the one you assign. One of those is ‘autodiscover’ (i.e. autodiscover.domainname.com). This is the host name used by the Outlook Anywhere feature for configuring Outlook automatically.
However, this is also the hostname that Outlook 2007 uses to search for the OAB. It is necessary then to add a cname record in DNS (or A record for that matter) pointing autodiscover to your e-mail server (don’t make the mistake of pointing to a mail gateway that is not Exchange). After this record is visible by the client computer, Outlook 2007 will find the OAB.
However, if a valid Unified Communications Certificate with the autodiscover host listed in the SAN is not installed on the server, Outlook 2007 will prompt a Certificate Warning. Users can then accept the certificate and move on, but it can become annoying, so it is important to get the correct cert.
What is a Unified Communications Certificate?
A Unified Communications Certificate is a certificate that allows you to specify multiple host/domain names for a single certificate. These additional names appear in a field called Subject Alternative Name (SAN).
TechNote Published By: INFINIT Consulting
*INFINIT TechNotes are provided solely for recommendation purposes and may not resolve each unique case. INFINIT Consulting will not be held liable for any issues arising from implementing the recommendations provided in this documentation.