SMTP PARAMETERS
The SMTPD module incorporates SMTP to handle connection requests and receive messages from peers on the Internet. This screen allows you to configure the different SMTP parameters used by SMTP. To configure, do the following:
- Enter the SMTP Ports:
- SMTPC port
The TCP port number that SMTPC will use to deliver messages to the Internet. The default value is 25.
- SMTPD port
The TCP port number that SMTPD will use to receive messages from the Internet. The default value is 25.
- Tick the check boxes of the ESMTP support features you wish to activate:
- Enable ESMTP
If enabled, SMTPD will support ESMTP. It will accept the ESMTP command EHLO. Other ESMTP extensions, such as SIZE, DSN, ETRN and 8-bit MIME, will also be supported. It is recommended that this option be kept enabled.
- Enable ESMTP SIZE
If enabled, SMTPD can issue the EHLO keyword SIZE in response to the EHLO command. You can configure the maximum inbound message size for each peer domain as well as the default maximum size under the Peer Configuration section. The optional parameter for the keyword SIZE, which is used to specify the allowed maximum size, can be determined from the Peer Configuration by taking the maximum value of the size limit for all the peer domains. This option is enabled by default.
- Enable ESMTP 8-bit MIME
If enabled, SMTPD will support 8BITMIME. This means SMTPD can accept messages with content body consisting of a MIME message containing arbitrary octet-aligned material. This option is enabled by default.
- Enable ESMTP ETRN
If enabled, SMTPD will accept ETRN requests. Once an ETRN request is received, SMTPD signals the SMTPC module to start a new queue processor for the requested ETRN host. This option is enabled by default.
- Enable ESMTP DSN
If enabled, SMTPD will accept a DSN request during MAIL FROM and/or RCPT TO commands. This option is enabled by default.
- Enable ESMTP AUTH
If enabled, SMTPD will accept an AUTH request and perform the user authentication. This option is enabled by default.
- Configure the SMTP AUTH parameters:
- Support LOGIN Mechanism
When enabled, the SMTP AUTH LOGIN authentication mechanism will be supported. This option is enabled by default.
- Support PLAIN Mechanism
When enabled, the SMTP AUTH PLAIN authentication mechanism will be supported. This option is enabled by default.
- Configure the SMTPD SSL parameters:
- Enable Security Support (SSL)
When the option is checked, SSL support for SMTPD server will be enabled. By default, it is not enabled.
- SSL Port Number
To specify the port number to be used for the SSL enabled SMTPD Server. The default value is 465.
- Configure the Delayed mail Notification parameters:
- Enable Delayed Notification
When enabled, the sender will receive a notification message from the SMTPC when the ESMTP DSN is disabled, or the DSN request does not specify NOTIFY-NEVER. This option is disabled by default.
- Enable successful Mail Notification
When enabled, Internet Exchange will send a notification message to the message sender stating that the delayed message has been successfully sent. The default is disabled.
- Send Delayed Notification after
The amount of time in hours that SMTPC will wait before sending a mail notification for delayed messages. The default value is 4 hours.
- Delayed mail notification text
The complete path and name of the file containing the message notifying the sender of a delayed message delivery. If a filename is not given or the file cannot be found at the specified path, a default warning message is used.
- Successful mail notification text
The complete directory location and name of the file containing the message to be sent to the Postmaster when the machine, after having sent at least one delayed message notification, eventually delivers the message. If no filename is specified, or if the file cannot be found at the specified location, a default warning message is sent.
- Specify the SMTP Timeout Tunings
- SMTPD
The timeout value (in minutes) that SMTPD waits on an open socket. This value should not be changed, but if unusual delays are being experienced, this can be adjusted to stop SMTPD from timing out. The default value is 5 minutes.
- SMTPC Initial
The amount of time (in minutes) that SMTPC waits for the initial contact of a remote host to be completed. The default value is 5 minutes.
- SMTPC Helo
This indicates the period (in minutes) that SMTPC will wait for the remote system to respond to the HELO command. The default value is 5 minutes.
- SMTPC Mail
The period (in minutes) that SMTPC will wait for the remote system to respond to the MAIL FROM command in the field . The default value is 5 minutes.
- SMTPC Rcpt
This refers to the period (in minutes) that SMTPC will wait for the remote system to respond to the RCPT TO command. The default value is 5 minutes.
- SMTPC Data
The period (in minutes) that SMTPC will wait for the remote system to respond to the DATA command in the field. The default value is 5 minutes.
- SMTPC Data Block
The period (in minutes) that SMTPC will wait for the remote system to respond and acknowledge the individual buffer transmission of message data. It can also be defined as the length of time wherein SMTPC waits between writes to the Winsock stack before it considers the remote system "dead". The default value is 5 minutes.
- SMTPC Data End
The period (in minutes) that SMTPC will wait for the remote system to respond to the DATA phase wrap up represented by the dot (.) command. The default value is 5 minutes.
- SMTPC Quit
The period (in minutes) that SMTPC will wait for the remote system to respond to the QUIT command. The default value is 5 minutes.
- Indicate the Data Buffer size, which refers to the size (in bytes) of the data buffer used by the SMTP programs to read data from the Internet. If the machine uses disk caching, set this option to the size of the read ahead buffer. The default value is 4096 (4K); the maximum buffer size is 32768 (32K).
- Tick the check box of the Set 554 SMTP error temporary option. RFC821 on SMTP is not clear as to whether error 554 transaction failed during the DATA phase should be regarded as a permanent error. Usually 5xx errors are permanent, but some SMTP servers return 554 errors as temporary errors. IEMS takes the conservative approach and re-tries such message later. If this option is set to NO, then such messages will be bounced instead or re-sent to their intended recipients. The default is YES.
- Click the Submit button to implement the settings.
NOTE:
To enable SSL support, you should first get a SSL server certificate (in PEM format) from a CA (Certificate
Authority) company. Append the server key (in PEM format) to the certificate file, and put the file on your server
machine located as
Under Linux: /opt/iems/stunnel.pem (where /opt/iems is the Installation directory of IEMS)
Under Win32: c:\iems\stunnel\stunnel.pem (where c:\iems is the Installation directory of IEMS)