Troubleshooting WF mailer issue

After EBS migrated to OCI and upgraded to Rel 12.2.10, users were complaining that they were not receiving emails

1. Validate that telnet to SMTP host is responding

Source(On Prem 11i)

[oracle@cm-prod ~]$ telnet relay.assaabloy.net 25
Trying 10.71.104.215…
Connected to relay.assaabloy.net.
Escape character is ‘^]’.

Target(OCI)

[applmgr@AM501AMERAP0001 log]$ telnet relay.assaabloy.net 25
Trying 10.71.104.215…
Connected to relay.assaabloy.net.
Escape character is ‘^]’.
220 DEMEESEX2001.ad.global Microsoft ESMTP MAIL Service ready at Sun, 21 Aug 2022 20:04:53 +0200

2. Executed $FND_TOP/sql/wfmlrdbg.sql for concerned notification (e.g161904398) as documented in the following note:

How to Run Script wfmlrdbg.sql and Collect its Output?( Doc ID 1364300.1 )

The output of wfmlrdbg.sql shows that REPLYTO is set incorrectly as NoReplyTO
This needs to be specified in email format.
Please change this to NoReplyTo@N0Domain.com and save.

Bounce the mailer and retest.

3. Validated the TEST mailer from EBS Workflow Front End

a) In the Service Components page for notification mailers in Oracle Applications Manager, select the Workflow Notification Mailer service component and click the View Details button > Click the Test Mailer button. Note: The test page lets you send a test e-mail to a workflow role.

b) In the Recipient Role field, select your user name from the list of values. Note: Only workflow roles with a notification preference set to receive e-mail and an e-mail address defined are included in the list of values for this field.

c) Click the Send Test Message button. In your preferred mail client, verify that the e-mail account associated with this e-mail address receives the test e-mail.

d) If you receive e-mail, then “workflow notification mailer” is working properly, else proceed with next step.

NOTE: Initially notification was not sent as MAIL_STATUS was NULL because notification_preference was set to QUERY for that username as seen in wfmlrdbg O/P.

Tested with TEST notification by sending it another user whose notification_preference is set to MAILHTML and test notifications were received by user.
Requested user to test with PO notification and it worked