If for some reason you turn the message store quota enforcement off, modify a user's quota, and then turn message store quota enforcement back on again, you should shut down SIMS. If you don't, it's possible that for a short period incoming mail to the modified user will be temporarily not delivered and returned to the sender. We absolutely recommend that you NOT turn the quota enforcement off to modify a user's quota, but in the very rare and unusual circumstance that you do, use the following procedure:
| 1. | Shut down SIMS | |
| 2. | Do whatever work you need to do with quota turned off | |
| 3. | Turn quota back on | |
| 4. | Run iminitquota -a | |
| 5. | Restart SIMS |
Here's an example of how a mail store full situation could occur, even though the mail store is not full: let's assume a user, Galaxion, has a user quota of 20 megabytes and is currently using 15 megabytes. Now, let's say the message store quota enforcement is turned off, and while it is turned off three things happen: 1) Galaxion's quota is reduced to 10 megabytes, 2) Galaxion deletes a bunch of mail and reduces her mail store usage to 7 megabytes, 3) An incremental directory synchronization occurs. Now, when quota enforcement is turned back on, iminitquota -a must be run to tally up mail storage usage. As soon as an incremental directory synchronization occurs, the system will start to enforce the new quota--in this case 10 megabytes. However, the system will read the old mail store usage value of 15 megabytes, until iminitquota -a is finished running. For 10,000 users this may take 30 minutes. So for that 30 minutes, the new quota of 10 megabytes may be used, but the old mail store usage value of 15 megabytes will be read. This causes the enforcement to stop accepting new mail.