ServiceNow instance can not connect to external third party Pop3 ServerIssue Troubleshooting guidelines for an "External/Third Party" Pop3 Server that cannot be accessed by a ServiceNow instance.CauseClient instance is utilizing a broken VPN connectionThere is a problem with ServiceNow's network connection to the client network and Pop3 ServerClient-side configuration have a problem like the Pop3 Service is down or perhaps a firewall issueResolutionDetermine the details regarding the Pop3 Service: Host Name and IP address.Determine if the client would use a VPN to connect to this particular Pop3 host. In case of client using a VPN connection: Check to see if the VPN configurations for the specific instance have an encryption domain setup that includes the IP address of the Pop3 mail server. Additionally, verify that both VPN connections are set up and configured (AHA Datacenters). Observe that traffic would be sent straight over the internet if the client is using a VPN and the IP address connected with the "Pop3 mail Server" is not in the encryption domain. Following questions may be asked by the administrators: Should the Pop3 Server's IP address be a part of the Encryption domain?So that this connection is routed over the VPN? The Pop3 host would have to be connected to the internet if not. And if not, the Pop3 would need to be added to the VPN configuration's Encryption domain. In either case, the connections from ServiceNow nodes can be tested. When using the command line interface (CLI) on the node, a port connection test should be used to see if the IP address can even be pinged. Ping the host, and if the host IP is accessible, check to see if the necessary ports are open (110 Pop3 port): nc -v {ipaddress} {port} If the Port can not be opened that could be related to: Pop3 Server being downFirewall related issuesNetwork related issues *(internet of Client side) Enlist the assistance of client-side network engineers if the host is unavailable, as it may be related to custom configurations such as firewalls, port mapping, etc. Related LinksUnable to add own POP3 servers in instance Email Account due to connection failure