JavaMail support for IPv6

WebSphere Application Server and its JavaMail component support Internet Protocol Version 6.0 (IPv6), meaning that:

Both can run on a pure IPv4 network, a pure IPv6 network, or a mixed IPv4 and IPv6 network.
On either the pure IPv6 network or the mixed network, the JavaMail component works with mail servers (such as the SMTP mail transfer agent, and the IMAP and POP3 mail stores) that are also IPv6 compatible. Additionally, a JavaMail component that is run on the mixed IPv4 and IPv6 network can communicate with
mail servers using IPv4.

Use of brackets with IPv6 addresses When you configure a mail session, you 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.

Related tasks
Configuring mail providers and sessions

Related reference