CleanMail System Requirements
CleanMail works with any existing mail server and is available as an installable software
product (Windows, Linux/i386),
or as a zero-maintenance hosted service
(requires a small change to the DNS/MX record of your domain).
Seamless Integration Into Your E-Mail Environment
CleanMail's transparent proxy architecture was designed to make the integration into existing E-mail environments simple and straight-forward.
CleanMail Server allows you to configure an unlimited number of SMTP/POP3 proxy ports or POP3 connectors (full multi-domain support).
CleanMail can be installed on your existing mail server and does not require additional hardware.
Configuration Options
Here is just a small selection of configuration options available in CleanMail:
Network Configuration Options
CleanMail Server can either be installed on separate hardware or on the same machine
as your current SMTP/POP3 mail server. It works with any SMTP or POP3 mail server or POP3-to-SMTP connector.
SMTP Proxy Options
- IP address/port number for incoming mail
- Outgoing mail server/port number
- Maximum resource usage
- Open relay protection: list of recipient address patterns where email is accepted
- Protection against directory harvesting attacks
- (optional) List of recipient address patterns with spam checking enabled
- (optional) SMTP Traffic limiting, to prevent mail flooding
POP3 Proxy Options
- Account and POP3 server information
POP3 Connector Options
- POP3 account and POP3 server network name or address
- Mail account and SMTP server network name or address
Available Mail Filters
- DNS Blacklist filter
- Attachment filter
- SpamAssassin Anti-Spam filter
- Anti-Virus filter: ClamWin already included as default, support for third-party anti-virus software from many vendors
- Delay Filter
- Mail storage: save all incoming mail to disk
- Spam trap filter: automatically learn spam mails sent to a honeypot address
- User-configurable filters
Filter Options
- Policy: reject/delete, reject/redirect, reject/deliver, accept/deliver,
configurable reply messages
- Recipient address patterns: where to apply a filter
All filters allow to choose what happens with a mail if the
filter finds unwanted content, such as a virus, or spam.
- accept/deliver (check disabled): A filter returns this result if the filter has been
disabled for all recipients of a message.
- accept/deliver: The filter did not find unwanted content.
- accept/deliver (skip size exceeded): Some filters do not check mails larger than
a configurable size. For example, spam mails are typically small, so the
SpamAssassin filter by default passes large mails without checking.
- accept/deliver (junk): The filter found unwanted content, but the mail is accepted
and delivered nonetheless.
- reject/deliver: The filter found unwanted content. Receipt of the mail is rejected
with a configurable Mail Rejection Message. The message is still
delivered to its recipients. Some filters (such as the SpamAssassin filter) tag
the message, so they can be quarantined by the mail server using filtering
rules.
- reject/redirect: The filter found unwanted content. Receipt of the mail is rejected.
The MTA that connects to CleanMail is supposed to notify the
user with a configurable Mail Rejection Message. The mail is redirected
to a quarantine account you can configure.
- accept/redirect: The filter found unwanted content. The mail is accepted. The
mail is redirected to a quarantine account you can configure.
- reject/delete: The filter found unwanted content. Receipt of the mail is rejected.
The MTA that connects to CleanMail is supposed to notify the user with a configurable
Mail Rejection Message. The mail is deleted.
- accept/delete: The filter found unwanted content. Receipt of the mail is acknowledged,
but the mail is deleted. The mail simply vanishes, the sender is not
notified, and the recipient never sees it.
- delete (unexpected client disconnect): The client disconnected without waiting
for the mail server to acknowledge receipt of the message. The mail was
probably spam, so good riddance. A legitimate sender will try to resend the
message later.
- reject/delete (mail too large): The mail was larger than the message size limit
you have configured. The message is rejected, and the MTA
that connects to CleanMail is supposed to notify the user with a configurable Mail
Rejection Message.
SpamAssassin™ Configuration Options
- Required score (how many filtering points are needed to flag a mail as spam?)
- Flag spam in subject line yes/no, configurable text
Read more about countless other SpamAssassin™ configuration options here:
http://spamassassin.apache.org/
Supported Standards
CleanMail complies to the following standards:
- Simple Mail Transfer Protocol (SMTP): RFC 2821
- Post Office Protocol Version 3 (POP3), RFC 1939
- Internet Message Format: RFC 822, RFC 2822, RFC 2045-2049, and RFC 2231
- SMTP Service Extensions, RFC 1869
- SMTP Service Extension for Authentication, RFC 2554
- SPF (Sender Policy Framework)
