RHEL Engineering is moving the tracking of its product development work on RHEL 6 through RHEL 9 to Red Hat Jira (issues.redhat.com). If you're a Red Hat customer, please continue to file support cases via the Red Hat customer portal. If you're not, please head to the "RHEL project" in Red Hat Jira and file new tickets here. Individual Bugzilla bugs in the statuses "NEW", "ASSIGNED", and "POST" are being migrated throughout September 2023. Bugs of Red Hat partners with an assigned Engineering Partner Manager (EPM) are migrated in late September as per pre-agreed dates. Bugs against components "kernel", "kernel-rt", and "kpatch" are only migrated if still in "NEW" or "ASSIGNED". If you cannot log in to RH Jira, please consult article #7032570. That failing, please send an e-mail to the RH Jira admins at rh-issues@redhat.com to troubleshoot your issue as a user management inquiry. The email creates a ServiceNow ticket with Red Hat. Individual Bugzilla bugs that are migrated will be moved to status "CLOSED", resolution "MIGRATED", and set with "MigratedToJIRA" in "Keywords". The link to the successor Jira issue will be found under "Links", have a little "two-footprint" icon next to it, and direct you to the "RHEL project" in Red Hat Jira (issue links are of type "https://issues.redhat.com/browse/RHEL-XXXX", where "X" is a digit). This same link will be available in a blue banner at the top of the page informing you that that bug has been migrated.

I've tried to follow the steps to reproduce this, but I did not get any error.
Please attach complete configuration (output of "doveconf -n"). Did you populate user test1's mailbox in any way? How exactly?

The Red Hat Enterprise Linux 7 life cycle has entered Maintenance Support Phase, which means that only qualified Critical and Important Security errata advisories (RHSAs) and some Urgent Priority Bug Fix errata advisories (RHBAs) will be released as they become available.  Unfortunately, this issue was not selected to be included in Red Hat Enterprise Linux 7, because it is seen either as low or moderate impact to a small number of use-cases. We will now close this issue, we recommend moving the request to Red Hat Enterprise Linux 8 if applicable.

See the Red Hat Enterprise Linux Life Cycle for more details:
https://access.redhat.com/support/policy/updates/errata/#Maintenance_Support_1_Phase