Protocol Not Supported Error During OAuth IMAP Configuration

Issue:

While setting up OAuth for IMAP in Oracle E-Business Suite R12.2, you may encounter the following error during the IMAP connection test:

IMAP connection testing failed with: Protocol not supported

This typically occurs after following the Oracle documentation Doc ID 2884072.1 for OAuth configuration.

Solution:

1. To resolve this, explicitly instruct the JVM to use the Sun HTTPS handler and enforce TLS 1.2 for outbound connections by updating the application tier startup parameters.

-DUseSunHttpHandler=true -Dhttps.protocols=TLSv1.2

2. Apply the changes by stopping and starting the application services:

adstpall.sh & adstrtal.sh