Disabling Mailbox verification on the SMTPRA service How to disable the mailbox check verification on the SMTPRA service in order to receive certain types of messages. When a message is sent with multiple recipients, the default behavior is to reject all the messages if one user does not exist or is overquota for the SMTP error codes as follows:

• 4XX over quota responses
• 5XX mailbox doesn't exist messages

In some circumstances, this is not a desired behavior, you can disable mailbox checking performed by SMTPRA (receiver agent) in the registry or in the SQL database if you are using SP-C. The mail receiver will not check whether a local recipient address actually exists. The recipient will be accepted. The Delivery service will issue a non-delivery report at a later stage if the recipient does not exist.

When this feature is disabled, the primary task of performing the task of mailbox checking is done by SMTPDA (delivery agent). You should be aware that this will add additional burden to the SMTPDA service. To disable mailbox checking at the SMTPRA service level, follow the steps below:

REGISTRY

WARNING!!
Incorrectly editing the registry can damage the server, please be sure you know what you are doing

1. Click on the start button
2. Select the run option
3. Type regedit, the registry editor will open
4. Select the HKEY_LOCAL_MACHINE key
5. Select the SYSTEM
6. Select CurrentControlSet
7. Select Services
8. Select SMTPRA
9. Select Parameters
10. Right click on the right pane and select NEW
11. Select DWORD Value
12. Name the new entry NoMailboxCheck
13. Double click the new NoMailboxCheck entry
14. Select decimal
15. To disable enter 1
16. close the registry editor

SQL (SP-C and SPS)

1. Click on the start button
2. Click on Programs
3. Click on Microsoft SQL server
4. Select Enterprise manager
5. Select the MailSite 5 Database
6. Right click on the MailServerProperties table
7. select Open table, Return all rows option
8. Add SMTPRA as a new entry in the ServiceName field
9. Add NoMailboxCheck in the ProperyName field
10. Add 4 in the PropType field
11. Add 1 in the PropIntValue field
12. Close enterprise manager.

All Changes made in the SQL database are immediate.