2231130 - XS612 Currently no delivery to RECIPIENT

• Messages (Email, Fax, etc.) being sent from the SAP system are failing in SOST with 'XS612 - Currently no delivery to RECIPIENT'.
• The long text of the XS612 message shows information like '452 4.3.1 Insufficient system resources' and '421 4.7.1 Recipient quota exceeded'.
• Example of long text showing '452 4.3.1 Insufficient system resources' can be seen in screenshot below:
  
  

• SAP Netweaver

• Release independent

3rd Party, mailserver, sapconnect , KBA , 421 4.3.2 service not available , 421 4.3.2 , 4.3.2 , 421 , service not available , BC-SRV-COM , Communication Services: Mail, Fax, SMS, Telephony , CRM-MKT-MPL-CPG , Marketing Planning and Campaign Management , Problem