Servers

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.

...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").

...ignores duplicate RCPT values within the same session

Enable this option if you want the SMTP server to ignore duplicate recipients in the same SMTP session. MDaemon will accept and then discard the duplicate recipients. This option is disabled 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 either a FROM: or a SENDER: header.

3.Have no more than one FROM: header.

4.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.

RFC required "DATE" header must also be present

Click this check box if you also wish to require a DATE header in each message.

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

Setting a value here will prevent MDaemon from accepting or processing 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. If you wish to exempt authenticated sessions from SIZE checks, use the "...but not if SMTP session is authenticated" option below.

...but not if the SMTP session is authenticated

Check this box if you wish to exempt messages from the message size limitation when the SMTP session is authenticated.

...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. Use "0" if you do not wish to set a limit.

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). Use "0" if you do not wish to set a limit.

Close session

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

POP & IMAP Servers

...POP server deletes mail on DELE command

Click this option if you wish MDaemon to delete messages immediately when they are retrieved and the DELE command is received, even if the POP session does not complete properly.

...IMAP server supports COMPRESS command

Click this box if you wish to support the IMAP COMPRESS extension (RFC 4978), which compresses all data sent to and from the client. COMPRESS will increase CPU and memory usage per IMAP session.

...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.

Server Options

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.