/mcpStep 2 Configure IP address access list (For more information, see Help> This Page): a) In the Edit menu, select Search IP Address Access List. b) In the Search IP Address Access List page, select Add New to add a new IP address to the list. c) In the New Access IP Address page, enter an IP address and select Save. d) In the Access IP Address page, to allow connections from the IP address, check the Allow Unity Connection check box and select Save. Configuring SMTP Message Parameters You can configure Unity Connection to reject any incoming SMTP messages that are larger than a configurable total size or have more than a configurable number of recipients. Step 1 In Cisco Unity Connection Administration, expand System Settings> SMTP Configuration and select Server. Step 2 In the SMTP Server Configuration page, in the Limit Size of Message field, enter a number in kilobytes to limit the size of an individual message sent by an SMTP client. Step 3 In the Limit Number of Recipients per Message field, enter the number of recipients allowed per message and select Save. Configure SMTP client communication Over STARTTLS on Port 25 Unity Connection Release 14SU1 and earlier, supports secure SMTP client communication. You can configure Unity Connection to support secure SMTP client interface using STARTTLS. Step 1 To enable Secure SMTP client feature, execute run cuc dbquery unitydirdb update tbl_configuration set valuebool='1' where name ='SmtpSecureClientEnabled' CLI command. By default this feature is disabled. Step 2 In Cisco Unity Connection Administration, expand System Settings> SMTP Configuration and select Server. Step 3 (Applicable to both Server and Client side configuration) On SMTP Server Configuration page check option Allow Connections From Untrusted IP Addresses. Make sure the value of field Transport Layer Security From Untrusted IP Addresses is is same on client and SMTP Smart Host. Cisco Unity Connection and SMTP client communication will be at port 25 using STARTTLS. Note Step 4 Select Save to apply the changes. Over STARTTLS on Port 25 and 587 using Authentication Support Unity Connection Release 14SU2 and later, supports secure SMTP client communication over port 25 and 587 using Authentication support. You can configure Unity Connection to support secure SMTP client interface using STARTTLS on port 587. You can also authenticate SMTP client interface using username and password. System Administration Guide 144 Messaging Configuring SMTP Message Parameters