- You add an external contact that uses a Microsoft account to a Skype for Business Online (formerly Lync Online) user’s contact list.
- The external contact uses a custom domain or an "email as sign in” (EASI) ID domain instead of a default @outlook.com address.
- You add the contact to Lync by using the contact’s email address. For example, you use the email address firstname.lastname@example.org.
- Presence is unavailable, and the status is displayed as Presence Unknown.
- Instant messages can't be delivered or sent.
- Skype for Business Online domain: contoso.com
- Windows Live EASI domain: live-contoso.com
Microsoft Lync 2013The best method to add external contacts in Lync 2013 is to use the Add Contact icon. For more info about how to add contacts through search or the add contact wizard, go to the following Microsoft website:
Microsoft Lync 2010Use the Microsoft account together with Public Internet Connectivity (PIC) when you add a user to your Lync contact list. To do this, you must make a change in the search field. A Skype for Business Online user who wants to add the Microsoft account that uses a custom domain, such as <username>@live-contoso.com, must add an address that resembles the following to the search field:
This method allows for a quick resolution if Skype for Business Online users are going to add only a few PIC contacts.
Alternative resolution by using DNSThe Skype for Business Online administrator must add the correct Service (SRV) Federation records to the Domain Name System (DNS) host for the Skype for Business Online environment. The domain owner for the external contact’s custom domain must also add an SRV record that resembles the following example:
port = 5061
server hostname = federation.messenger.msn.com
If you directly add a PIC contact by using the contact’s EASI ID (for example, you use JoeAndreshak.@live-contoso.com), a specific SRV record is required in the DNS for live-contoso.com. This SRV record is required because the Skype for Business Online server uses the domain suffix in the user's EASI ID to determine how to route messages. In this example, the Skype for Business Online server tries to use the live-contoso.com domain suffix.
For more info about how to troubleshoot Skype for Business Online federated contacts, click the following article number to view the article in the Microsoft Knowledge Base
Article ID: 2566829 - Last Review: Dec 16, 2016 - Revision: 1