SUMMARY

This article provides information on how to configure MailEnable to cater for Microsoft Outlook autodiscover requirements. By configuring autodiscover in MailEnable, Microsoft Outlook users have the benefit of just using their email address and password in order to create accounts. Autodiscovery with Outlook supports IMAP, POP, SMTP and ActiveSync configurations. Other clients may also support autodiscover, but this article just describes usage with Outlook.

INFORMATION

Configuration of the Autodiscover is done through the administration program. It can be either done globally, or at the postoffice level if you are using MailEnable Enterprise or Enterprise Premium. To configure globally, expand the Servers branch in the administration program, right click on the localhost icon and select Properties in the popup menu. In the window that appears, click the Autodiscovery tab.

Under the Protocols heading you can add the protocols you are wishing to use for Outlook. You can use the Detect button to automatically populate with recommended settings, or add manually. Outlook will choose IMAP or POP before it chooses ActiveSync. So if you wish your clients to just use ActiveSync with Outlook, then you will need to remove POP, IMAP and SMTP protocols. If these exist, Outlook will use them instead of ActiveSync.

When using IMAP, POP and SMTP protocols, Outlook does not support a username with a domain. So if your mailbox is not in the default postoffice, the login will fail and the user will be prompted for the correct credentials in Outlook. If you are using Enterprise or Enterprise Premium you can solve this by binding your domains to IP addresses and configuring autodiscover per domain. If you are using the Professional version of MailEnable there is not this ability.

Once the configuration is done in the administration  program you still need to ensure that clients can connect to the autodiscover service to get the settings. This is done by making sure you have the correct DNS entries and domain names configured under IIS.

For Autodiscover DNS records:

1. Create a CNAME record in your local DNS server under the domain that will be used for autodiscover (or via your hosting provider hosting the DNS server). I.e.: autodiscover.exampledomain.com
2. Create an SRV record within your local DNS server for the domain
3. Obtain an SSL certificate for the server/domain. MailEnable recommends obtaining a wildcard SSL certificate also named Unified communication certificate so that it can cater for all names of the domain. I.e.: mail.exampledomain.com and autodiscover.exampledomain.com

Add an SSL certificate under the MailEnable Protocols website:

1. Open the Microsoft Internet Information Services control panel applet.
2. Expand the folder tree and click on the MailEnable Protocols site.
3. In the "Actions" pane click on "Bindings" and then on the "Add" button.
4. Select HTTPS under the "type" selection and then select the IP the domain is bound to.
5. Under the SSL certificate select the autodiscover certificate and then click OK. The autodiscover certificate must be autodiscover.example.com (where example.com is the domain you are configuring). 
6. Click Add again and select HTTP as the type of binding and then select the IP that is bound to CNAME created in DNS. I.e.: autodiscover.example.com
7. Click OK.

TROUBLESHOOTING

The best way to test auto discover is to use the Microsoft Exchange test connectivity website located here:

https://testconnectivity.microsoft.com/

MailEnable also provides a tool for testing auto discover located here:

http://www.mailenable.com/tools/

MORE INFORMATION

When Microsoft Outlook tries to autodiscover during the account setup process it will try to connect to a special URL, or uses a special DNS query (SRV record). An ordered list of DNS records and URLs can be found below:

1. Tries to retrieve https://example.com/Autodiscover/Autodiscover.xml. The example.com is the email domain part of the email address used in account settings.
2. If that fails, it tries to retrieve https://autodiscover.example.com/autodiscover/autodiscover.xml.
3. If that fails, a DNS SRV lookup is done on _autodiscover._tcp.example.com. If the SRV record exists for the domain it will return the host name of the server: I.e.: "mail.example.com".
4. The host name given from the SRV lookup is then used, e.g. https://mail.example.com/autodiscover/autodiscover.xml.

Microsoft Outlook uses https to access the autodiscover service when connecting to an EAS server. Therefore a valid and trusted SSL certificate is required.

While Outlook will still be able to autodiscover if the certificate is not trusted the end user will need to trust the certificate and therefore the Outlook client will always prompt when the client is opened and contacts the server for the first time.

REFERENCES

MailEnable Exchange ActiveSync Deployment guide: http://www.mailenable.com/activesync/EAS_Deployment_Guide.pdf