You really need to provide more information.
Which EV Version. What mail-platform/version. Arching items older than 3 months. Items in mailbox are older than 3 months. How many items. If you check properties of these items, are they indeed >3 months? (modified date). Any events on EV server? Mailbox size? Number of items in a mailbox?
Enterprise Vault: version: 184.108.40.2061
MailBox Server:Exchange 2016 （2 NODE DAG architecture）
Mails that are more than 3 months old are 5,582 items，Each mailbox has unlimited capacity，From the two mailboxes we observed, the number of emails was more than 7,000.Enterprise Vault does not find any events other than those that successfully start the task.
But one thing, these emails in the old Exchange Server and Old EV 12.4 Server have been archiving but not successful, then migrated to the new mail server, use the new EV12.5, after DocMessageClass tool to IPM. Note. EnterpriseVault. PendingArchived changed to IPM. Note(https://www.veritas.com/support/en_US/article.100017789), that's all.
Ah... The items you converted back to IPM.Note are considered to be archived already, and will therefor not archive again.
You have 2 options, both of these are descibed in the Registry Guide.
1 ClearDoNotArchive - create below registry key, restart archiving task. Then perform a 'run now' against the mailboxes that have issues. If it works, great, remove registry key (or set to 0), restart taks again. If it does not work, remove key, restart task, attempt 2
DWORD = ClearDoNotArchive
Value = 1
2 - IgnoreEVDates - set below 2 registry keys. restart archiving task, perform a run now against the mailbox not archiving. If it works, remove keys again, restart task again. If this does not work, call support (again).
DWORD = IgnoreEVDates
Value = 1
STRING = IgnoreEVDatesEnd
Value = 20201101T00:00:00Z
(date = 01 november 2020)
If they do not archive, examine the properties of one of the items. Check the modified date, and see what that says.
It might be you need to play around a bit. It might be the layout is wrong.
See this KB again: https://www.veritas.com/content/support/en_US/article.100022437
Location: HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\KVS\Enterprise Vault\Agents
Content: String value containing a UTC date and time in the following ISO 8601 format: yyyyMMddThh:mm:ssZ
Sets the date that the IgnoreEVDates registry value uses as the latest Archived or Restored date.
These settings are global and will apply to the whole organization. If only certain mailboxes need to be targeted, a manual run now can be done on those specified mailboxes and the registry key removed after archiving is complete.
By design this setting will not apply to non-shortcut type items such as: calendar, contacts, tasks, etc. Refer to 100026773 below for further information regarding this.
These settings will only apply during Run Now archiving operations, not during scheduled archiving operations.
Re-reading, I would set to date to yesterday's date, and try again
I just want to archive all emails that have not been archived before October 1, 2020. Any emails after this date will not be archived. How should I set this value: yyyyMMddThh:mm:ssZ.
Even if I set yesterday's date to January 24, 2021, there will still be a warning after rerunning the task "
The mailbox archiving task is configured to ignore archived and / or restored dates whenever it is manually run, using the IgnoreEVDates registry key, but is missing the required IgnoreEVDatesEnd registry key.For more information, see Help and Support Center at http://telemetry.community.veritas.com/entt?product=ev&language=english&version=220.127.116.11&build=12.5....91
I lost my way
It might be the key is corrupt. Can you delete it, and recreate it?
I assume you have a support contract, as you mentioned support did not get you any further. It might be an idea to call them again, explain you want to use the 2 regirsty keys, and then explain you need the exact format for the IgnoreEVDatesEnd registry entry. I do not use mailbox archiving, so I cannot test for you.
I have seen a rare case where this is not the root cause of the issue and there was some intermediatry software touching the items all the time, which caused an issue for archiving. If the above does not help you, you have to go into the wonderful world of MFCMAPI to look at items, save their properties, and review the dates in question. I have never seen EV mess this up, but there has been a few instances of expectations and reality being misaligned.