JavaMail support for IPv6

WebSphere Application Server and its JavaMail component support Internet Protocol V6.0 (IPv6), meaning that:

Use of brackets with IPv6 addresses

When you configure a mail session, we can specify the mail server hosts (also known as mail transport and mail store hosts) with domain-qualified host names or numerical IP addresses. Using host names is generally the preferred method. If you use IP addresses, however, consider enclosing IPv6 addresses in square brackets to prevent parsing inaccuracies. See the following example:

[fe80::202:57ff:fec4:2334]
The JavaMail API requires a combination of many host names or IP addresses with a port number, using the host:port number syntax . This extra colon can cause the port number to be read as part of an IPv6 address. Using brackets prevents your JavaMail implementation from processing the extra characters erroneously.