Assume that you use a Dynamic Minimal Lower Layer Protocol (MLLP) One-Way Send in Microsoft BizTalk Server, and the MLLP-specific Solicit Response Enabled property is set to Yes. In this situation, the Send may fail with the warning Event ID 8455:
"Acceptable ACK Codes" is ignored on Send Port, as the port is a one-way send port with Solicit Response value set to 'No'”
This issue is fixed in the following cumulative updates for BizTalk Server:
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
For information about the service packs and cumulative update list for BizTalk Server, click the following article number to view the article in the Microsoft Knowledge Base:
2555976 Service pack and cumulative update list for BizTalk Server
For more information about BizTalk Server hotfixes, click the following article number to view the article in the Microsoft Knowledge Base:
2003907Information about BizTalk hotfixes and Service Pack support