Microsoft SMTP Service maintains the metabase properties listed below.
| AllowVerify |
| Datatype: Boolean |
| Default: True |
| Can be configured at: IIsSmtpService, IIsSmtpServer |
| This value enables or disables the Vrfy command, which allows remote clients to verify whether local mailboxes exist. |
| AlwaysUseSsl |
| Datatype: Boolean |
| Default: False |
| Can be configured at: IIsSmtpService, IIsSmtpServer |
| A value of True specifies that all outgoing transmissions are encrypted. Messages are then transmitted over a secure line and decrypted by the receiving server. This option can be overridden for a specific remote domain by selecting or clearing the TLS encryption check box in the Domain property sheet for that domain. For example, if you do not want to use Transport Layer Security (TLS) for all transmissions but you send messages regularly to a remote site that requires the use of TLS for all incoming transmissions, set AlwaysUseTls to False. Then create a remote domain for the remote site, and select the TLS encryption check box for the domain. Alternatively, you can turn on the TLS bit in the RouteAction metabase property. |
| AuthTurnList |
| Datatype: Multi-Sz |
| Can be configured at: IIsSmtpDomain |
| This list of strings provides the user names of clients who have permission to use the Turn command. Microsoft SMTP Service requires that these clients use authentication (clear text or NT Challenge/Response). In addition, clients may use TLS encryption. |
| BadMailDirectory |
| Datatype: String |
| Default: c:\InetPub\MailRoot\Badmail |
| Can be configured at: IIsSmtpService, IIsSmtpServer |
| This value specifies the path of the Badmail directory. When a message is undeliverable or corrupt for any reason, it is returned to the sender with a non-delivery report (NDR). If the NDR cannot be delivered to the sender, a copy of the message is put in the Badmail directory. If the Badmail directory does not exist, the message is left in the Queue directory, and its file extension is changed to .bad. |
| BatchMessages |
| Datatype: Boolean |
| Default: True |
| Can be configured at: IIsSmtpService, IIsSmtpServer |
| A True value specifies that the SMTP server computer should batch outgoing messages sent to the same remote host instead of opening a new connection for each message. |
| DefaultDomain |
| Datatype: String |
| Default: [Based on the TCP/IP value in the registry. This can be also be set in the Microsoft TCP/IP Properties sheet in the Network application in Control Panel.] |
| Can be configured at: IIsSmtpService, IIsSmtpServer |
| This value specifies the default local domain. SMTP stamps the default domain on addresses that do not have a domain specified. For example, if the default domain is Microsoft.com and a local client sends a message to Joe, the address will be stamped with the default and sent to Joe@Microsoft.com. A single instance of Microsoft SMTP Service (called a site) can have only one default domain. |
| A local domain can also be an alias or a normal domain. Mail sent to an alias domain will be routed to the default domain; the alias is a "masquerade" of the default. A normal domain can be one of many "virtual" domains at an SMTP site. Each normal domain has its own namespace; that is, it is not an alias for the default domain. |
| DoMasquerade |
| Datatype: Boolean |
| Default: False |
| Can be configured at: IIsSmtpDomain |
| A value of True enables a masquerade domain for this domain. The name of the masquerade domain is set in MasqeradeDomain. |
| DropDirectory |
| Datatype: String |
| Default: C:\INetPub\Mailroot\Drop |
| Can be configured at: IIsSmtpService, IIsSmtpServer |
| This value specifies a directory to receive all incoming messages and to store all mail for this local domain. The Drop directory must be on a local drive. |
| EnableReverseDnsLookup |
| Datatype: Boolean |
| Default: False |
| Can be configured at: IIsSmtpService, IIsSmtpServer |
| This flag indicates whether a Reverse DNS Lookup will be attempted on incoming connections. If the Reverse DNS Lookup is successful, SMTP includes the domain name for the IP address in the Received message header. If unsuccessful, SMTP puts in only the IP address. Because a Reverse DNS Lookup is a resource-intensive operation, the default value of this property is False. |
| FullyQualifiedDomainName |
| Datatype: String |
| Default: [Based on the TCP/IP value in the registry. This can be also be set in the Microsoft TCP/IP Properties sheet in the Network application in Control Panel.] |
| Can be configured at: IIsSmtpService, IIsSmtpServer |
| For SMTP to properly process mail exchanger (MX) resource records, SMTP must have a distinct, fully-qualified domain name (FQDN) for each SMTP site. The FQDN is the unique name that identifies the mail server in the DNS domain. In the MX entry, the mail domain maps to the FQDN. There must also be an address (A) resource record mapping the FQDN to an IP address. Specifically, the FQDN is used to ensure that mail is forwarded only to mailers of higher priority than the current server. |
| HopCount |
| Datatype: Long |
| Range: 1 - unlimited |
| Default: 10 |
| Can be configured at: IIsSmtpService, IIsSmtpServer |
| This value specifies the maximum number of times a message can be sent between mail servers. The SMTP server counts hop using the Received header in the message. If SMTP receives a message which has more Received headers than this limit, SMTP sends an NDR to the original sender. |
| LimitRemoteConnections |
| Datatype: Boolean |
| Default: False |
| Can be configured at: IIsSmtpService, IIsSmtpServer |
| This flag indicates whether outgoing connections are limited. If it is enabled, connections are limited. The number of concurrent outgoing connections allowed is set in MaxOutConnections. The default is 1000. |
| LocalRetryAttempts |
| Datatype: Long |
| Default: 48 |
| Can be configured at: IIsSmtpService, IIsSmtpServer |
| This value specifies the maximum number of attempts that are made to deliver a message locally before the message is returned to the sender with an NDR. A value of zero means that an NDR is sent on the first failure to deliver. |
| MasqueradeDomain |
| Datatype: String |
| Default: [blank] |
| Can be configured at: IIsSmtpService, IIsSmtpServer |
| This string creates an alias local domain. SMTP uses this alias to replace the default local domain in From lines (in the header) or Mail From lines (in the protocol), thus hiding the source of messages. Leaving this value blank disables this feature. |
| MaxBatchedMessages |
| Datatype: Long |
| Range: 1 - unlimited |
| Default: 20 |
| Can be configured at: IIsSmtpService, IIsSmtpServer |
| This value specifies the maximum number of messages that can be grouped together to send to the same domain over a single connection. |
| MaxMessageSize |
| Datatype: Long |
| Range: 1 - 209715 (Kilobytes) |
| Default: 2048 |
| Can be configured at: IIsSmtpService, IIsSmtpServer |
| This value specifies the preferred message size limit for the server; this is the limit that is advertised to remote clients. However, the message is still processed as long as its size does not exceed the value for MaxSessionSize; if the size does exceed this value, the connection is closed automatically. |
| MaxOutConnections |
| Datatype: Long |
| Range: 1 - unlimited |
| Default: 1000 |
| Can be configured at: IIsSmtpService, IIsSmtpServer |
| If outbound connections are limited because LimitRemoteConnections is enabled, this value specifies the maximum number of concurrent outgoing connections that are allowed. |
| MaxOutConnectionsPerDomain |
| Datatype: Long |
| Range: 1 - unlimited |
| Default: 100 |
| Can be configured at: IIsSmtpService, IIsSmtpServer |
| This value specifies the maximum number of outbound connections that are allowed to any single remote domain. This is a subset of MaxOutConnections. |
| MaxRecipients |
| Datatype: Long |
| Range: 100 - unlimited |
| Default: 100 (minimum, according to RFC 821) |
| Can be configured at: IIsSmtpService, IIsSmtpServer |
| This value specifies the maximum number of recipients that are allowed for a single incoming message. |
| MaxSessionSize |
| Datatype: Long |
| Range: 1 - 209715 (Kilobytes) |
| Default: 10240 |
| Can be configured at: IIsSmtpService, IIsSmtpServer |
| This value specifies the maximum size of a message before Microsoft SMTP Service terminates the socket session. This value is always larger than the value for MaxMessageSize. It should be set carefully because the connecting SMTP server computer is likely to keep resubmiting the same message. |
| PickupDirectory |
| Datatype: String |
| Default: C:\INetPub\Mailroot\Pickup |
| Can be configured at: IIsSmtpService, IIsSmtpServer |
| This value provides the path for a mail "pickup" directory. If the files placed in this directory comply with RFC 822, Microsoft SMTP Service treats them like messages and places them in the Queue directory. |
| QueueDirectory |
| Datatype: String |
| Default: C:\InetPub\Mailroot\Queue |
| Can be configured at: IIsSmtpService, IIsSmtpServer |
| This value provides the path for the directory that holds all messages for delivery. If a message cannot be sent because the connection is busy or down, the message is stored in the queue and resent at designated retry intervals. |
| RelayForAuth |
| Datatype: Long |
| Default: 0 |
| Can be configured at: IIsSmtpDomain |
| A Nonzero value sets a requirement that only authenticated mail (NTLM or clear text) may be relayed through domain. |
| RemoteRetryAttempts |
| Datatype: Long |
| Range: 0 - unlimited |
| Default: 48 |
| Can be configured at: IIsSmtpService, IIsSmtpServer |
| This value specifies the maximum number of times an outbound message is resent before it is returned to the sender with an NDR. A value of zero means that an NDR is sent after the first failure to send. |
| RemoteRetryInterval |
| Datatype: Long |
| Range: 1 - unlimited (minutes) |
| Default: 60 |
| Can be configured at: IIsSmtpService, IIsSmtpServer |
| This value specifies the amount of time the system waits between each attempt to resend an outbound message. The minimum value is zero, which indicates that an NDR will be sent on the first failure. |
| RemoteSmtpPort |
| Datatype: Long |
| Range: 0 - unlimited |
| Default: 25 |
| Can be configured at: IIsSmtpService, IIsSmtpServer |
| This value specifies the port on a remote SMTP server computer to which Microsoft SMTP Service will connect. |
| RoutingDll |
| Datatype: String |
| Default: C:\WinNT\System32\INetSrv\Routeht.dll |
| Can be configured at: IIsSmtpService, IIsSmtpServer |
| This DLL file looks up mail addresses in the Routing table and returns the locations of local mailboxes. |
| RouteAction |
| Datatype: Long |
| Can be configured at: IIsSmtpDomain |
| This bit mask enables routing options for domains. The mask is 32 bits in length; the first 20 bits (left to right) are reserved for future use and are always zero. An option is enabled by changing its corresponding zero bit to 1. Depending on which flags are turned on, related value strings are stored in RouteActionString, RouteUserName, and RoutePassword metabase properties. |
| The following table contains the bit flags, starting with the lower bits: |
| Flag | Bit number | Function |
| Drop |
31, or 0x00000001 hexadecimal |
Enables a Drop directory for this domain. RouteActionString contains the path of the Drop directory. |
| Remote Domain |
30, or 0x00000002 hexadecimal |
Enables a remote domain. RouteActionString contains the domain name of the route domain for this remote domain, if it exists. |
| TLS |
29, or 0x00000004 hexadecimal |
Enables TLS encryption with the route domain. |
| SASL |
28, or 0x00000008 hexadecimal |
Enables an authentication logon process. If this flag is on, an authentication method must also be chosen, either clear text (bit 23) or Windows NT Challenge/Response (bit 24). The user name and password are stored in RouteUserName and RoutePassword, respectively. |
| Alias |
27, or 0x00000010 hexadecimal |
Enables an alias for the default domain. RouteActionString contains the alias domain name. |
| Deliver |
26, or 0x00000020 hexadecimal |
Enables delivering to mailboxes for this domain. |
| Auth Ntlm |
24, or 0x00000080 hexadecimal |
Enables Windows NT Challenge/Response as an authentication method. Simple Authentication and Security Layer (SASL) (bit 28) must also be on. |
| Auth ClearText |
23, or 0x00000100 hexadecimal |
Enables basic authentication (AUTH=LOGIN) as an authentication method. SASL (bit 28) must also be on. |
| Etrn Cmd |
22, or 0x00000200 hexadecimal |
Enables the Extended Turn (Etrn) command to be sent to the smart host server. RouteActionString contains the Etrn domain name. |
| Domain Relay |
21, or 0x00000400 hexadecimal |
Enables sending mail to this remote domain. (Remote domain (bit 30) must also be on.) The default is that mail cannot be sent remotely. |
| RouteActionString |
| Datatype: String |
| Can be configured at: IIsSmtpDomain |
| This value provides a Drop directory path, a smart host server name, or an alias domain name, according to how the RouteAction bit mask is configured. |
| RouteUserName |
| Datatype: String |
| Can be configured at: IIsSmtpDomain |
| This value provides the user name that is used with authenticated logons to remote servers when the SASL bit is turned on in the RouteAction bit mask. |
| RoutePassword |
| Datatype: String |
| Can be configured at: IIsSmtpDomain |
| This value provides the password that is used with authenticated logons to remote servers when the SASL bit is turned on in the RouteAction bit mask. |
| SaslLogonDomain |
| Datatype: String |
| Default: [blank] |
| Can be configured at: IIsSmtpService, IIsSmtpServer |
| This string provides a default domain name that can be used for configuring inbound security. If a user specifies a user name only, this domain name will be used to complete the string. For example, if the SaslLogonDomain is Ultra, and the user specifies Man, the account name is configured as Ultra/Man. |
| SendNdrTo |
| Datatype: String |
| Default: Postmaster@<default domain>.com |
| Can be configured at: IIsSmtpService, IIsSmtpServer |
| A copy of all NDRs sent by the SMTP site are sent to this address. An empty string disables this feature. |
| SmartHost |
| Datatype: String |
| Default: [blank] |
| Can be configured at: IIsSmtpService, IIsSmtpServer |
| This string provides the domain name of a smart host server. When this property is populated, Microsoft SMTP Service disregards the address in the Rcpt To header in the protocol and routes the message to the smart host server. The exception is mail sent to a domain associated with a route domain; this mail is routed to the route domain instead of the smart host server. |
| SmartHostType |
| Datatype: Long |
| Range: 0-2 |
| Default: 1 |
| Can be configured at: IIsSmtpService, IIsSmtpServer |
| This parameter enables mail to be routed to a smart host server. SMTP then sends all received mail to the domain given at SmartHost in the Delivery property sheet, disregarding addresses in the Rcpt To header in the protocol. The values are as follows: |
|
0 = DonÆt use the smart host server, even if SmartHost contains a string. 1 = Send mail to the smart host server using the domain name contained in SmartHost after the first failure to deliver to a route domain or to the address specified in the Rcpt To header in the protocol. 2 = Always send mail to the smart host server using the domain name contained in SmartHost. The exception is mail sent to a domain associated with a route domain; this mail is routed to the route domain instead of the smart host server. |
| SmtpClearTextAuthProvider |
| Datatype: String |
| Can be configured at: IIsSmtpService, IIsSmtpServer |
| This string provides the name of the clear text authentication package (such as DPA). |