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SMTP Server...

...honors VRFY

Click this switch if you wish to respond to SMTP VRFY commands. This command is sometimes used by servers that use an SMTP call forward or call back feature to attempt to confirm the validity of email addresses on your server. This is disabled by default.

...honors EXPN

Click this checkbox if you want MDaemon to honor EXPN commands.

...does not advertise SIZE

Click this checkbox if you want the SIZE command parameter to be hidden.

...honors APOP & CRAM-MD5

By default MDaemon's servers (POP, IMAP, and so on) honor the APOP and CRAM-MD5 methods of authentication. These methods provide extra security by making it possible for users to be authenticated without sending clear text passwords. Clear this checkbox if you do not wish to allow APOP or CRAM-MD5.

...sends 552 when account is over quota (otherwise sends 452)

Enabling this option will cause a 552 response ("Requested mail action aborted: exceeded storage allocation") when delivery is attempted to a recipient whose account exceeds its quota. Normally there would be a 452 response ("Requested action not taken: insufficient system storage").

...uses ESMTP when possible

When this option is enabled, MDaemon will support extended SMTP commands. This is enabled by default.

...refuse messages which are not RFC compliant

Enable this option if you wish to reject messages during the SMTP process that are not compliant to RFC internet standards. To pass the compliance test the message must:

1. Be greater than 32 bytes in size (the minimum size necessary to include all required parts).
2. Have a DATE: header.
3. Have either a FROM: or a SENDER: header.
4. Have no more than one FROM: header.
5. Have no more than one SUBJECT: header, though no subject header is required.

Messages using authenticated sessions or from trusted domains or IP addresses are exempt from this requirement.

...refuses messages larger than [xx] KB (0=no limit)

Setting a value here will prevent MDaemon from accepting or processing SMTP delivered mail that exceeds a certain fixed size. When this option is enabled MDaemon will attempt to use the ESMTP SIZE command specified in RFC-1870. If the sending agent supports this SMTP extension then MDaemon will determine the message size prior to its actual delivery and will refuse the message immediately. If the sending agent does not support this SMTP extension then MDaemon will have to begin acceptance of the message, track its size periodically during transfer, and finally refuse to deliver the message once the transaction has completed. Use "0" in this option if you do not wish to set a size limit.

...drops connection if transmission exceeds [xx] KB (0=never)

If the transmission of data during an MDaemon connection exceeds this threshold, MDaemon will close the connection.

...allows only this many RCPT commands [xx] (RFC says 100)

Use this option if you wish to limit the number of RCPT commands that can be sent per message.

Close session

Check this box if you wish to close the session immediately if the maximum allowed number of RCPT commands is reached.

...allows only this many RSET commands [xx]

Use this option if you wish to set a maximum number of RSET commands allowed in an SMTP session (default is 20).

Close session

Check this box if you wish to close the session immediately if the maximum allowed number of RSET commands is reached.

POP3 / IMAP Servers

...immediately delete mail upon a DELE command

Click this option if you wish MDaemon to delete immediately messages that a user has retrieved even if the POP session does not complete properly.

...maximize use of stack memory (POP3 only - may cause instability)

This option maximizes MDaemon's use of stack memory to avoid problems that can occur in situations where active POP accounts may contain many thousands of messages. If you disable this option then the POP server will be more conservative but you could notice a decrease in interface responsiveness when the POP server is under a heavy load.

...always allow connections from this IP

The POP and IMAP servers will always accept connections from the IP Address entered into this field regardless of screening and shielding settings.


Allow plain text passwords

This option governs whether or not MDaemon will accept passwords sent in plain text to the SMTP, IMAP, or POP3 servers. If disabled, the POP3 USER, POP3 PASS, IMAP LOGIN, IMAP AUTH LOGIN, and SMTP AUTH LOGIN commands will return an error unless the connection is using SSL.

Allow connections to own IP addresses

When this option is enabled, MDaemon can connect to itself.