Ideation: New User and Password Reset emails aren't getting sent

Issue Summary

• Ideation-related messages (both new user and password reset) aren't getting sent

Error logs in Splunk:

{ [-]
   Level: Error
   MessageTemplate: Email not sent
   Properties: { [-]
     Build: 10.96.0.17420
     EmailId: <id>
     Instance: INSTANCE
     MachineName: NAME
     Product: AgileCraft.Backbone
     ServiceName: AgileCraft_BackOffice_INSTANCE
     Task: SendMail
     TaskId: 9
     TaskOccurrenceCorrelation: 1331724706
     ThreadId: 132
     reason: Not a password email
   }
   Timestamp: 2021-06-09T10:09:50.9909061-04:00
}

Steps to Reproduce

Use-case1 : New user enrollment

1. As a new user, register to instance's ideation portal
2. As Jira Align Admin, browse to Email Log and notice the new user email hasn't been sent (error:5)

Use-case2 : Password Reset

1. As an existing user, browse to instance's ideation portal
2. Proceed with password reset request
3. Notice the green toaster confirming the request has been placed
4. As Jira Align Admin, browse to Email Log and notice the password reset email hasn't been sent (error:5)

Expected Results

• New User registration email is sent
• Password Reset email is sent

Actual Results

• No emails are sent

Workaround

We did an investigation and looks like there is an edge case when we validate the email subject when Send only password emails dropdown is set to Yes option.
To skip that case of validation, please set Send only password emails to No on Email Settings page.