It seems to me that Microsoft hides the links to these forums.  You can find them on the Microsoft site, but they are buried under a drop-down list with about 100 other forums.

You can ask questions and get answers in the forums below on the MSDN site (http://Social.Msdn.Microsoft.com).  You can also get good answers in StackOverflow.com.

Some people are still using the forums at BizTalk Gurus: http://www.biztalkgurus.com/forums/

 

BizTalk Geenral: https://social.msdn.microsoft.com/Forums/en-US/home?forum=biztalkgeneral&filter=alltypes&sort=lastpostdesc

 

BizTalk EDI: https://social.msdn.microsoft.com/Forums/en-US/home?forum=biztalkediandas2&filter=alltypes&sort=lastpostdesc

 

Adapters and Adapter Pack: https://social.msdn.microsoft.com/Forums/en-US/home?forum=biztalkr2adapters&filter=alltypes&sort=lastpostdesc

 

BizTalk RFID: https://social.msdn.microsoft.com/Forums/en-US/home?forum=biztalkrfid&filter=alltypes&sort=lastpostdesc

 

BizTalk ESB Toolkit:  https://social.msdn.microsoft.com/Forums/en-US/home?forum=biztalkesb&filter=alltypes&sort=lastpostdesc

You can post a new question/issue to the MSDN Community Forum here:
https://social.msdn.microsoft.com/Forums/en-US/newthread

When you select “BizTalk Server” fro the “Forum category”, you will then get the list of specific BizTalk Forums on the right, as shown below: