1649464 - SMTP 421 - Service not available, closing transmission channel FBE60013

• When 22 recipients are selected in a a publication and the publication is scheduled  it fails with following error:

Distribution to destination CrystalEnterprise.Smtp (To: name@company.com) failed. Recipient: a22, Document Scope:  Sample : 6926 (Webi) : (AND ). address error. [[] ([22]/[22])]:

[Error sending address(es) to SMTP server. Return code: [SMTP 421 - Service not available, closing transmission channel.]. Reason:

[name@company.com].] (FBE60013) [22 recipients processed.]

• When 21 recipients are selected publication works fine.

• SAP business objects BI Platform 4.0 all Patches 
• Microsoft Exchange Server  all versions
• Issue not reproduced with Lotus Domino server

Microsoft Exchange Mail Server SMTP 22 21 external recipients publication report bursting , KBA , BI-BIP-PUB , Publishing and scheduling in InfoView/BI launch pad , Problem