VPS2 Mail Server: sendmail
 E-mail services on your Virtual Private Server are managed by the sendmail program, with various other
E-mail tools providing extended capabilities.
sendmail is a configurable, robust SMTP server that processes all incoming and outgoing messages on your
VPS2. Any VPS2 Users can send and receive e-mail messages with
sendmail, although in order to check or send E-mail from a remote client (such as Outlook or Eudora), the
user must also have POP or IMAP permissions.
Configuring sendmail
The sendmail program on VPS2 runs as a daemon (a program that is always running). When
you make changes to any of the sendmail configurations, you must restart sendmail to load
the new settings into the daemon. For configuration info see:
http://support.alpineweb.com/hosting/vps/freebsd/admin/email/sendmail/index.html
Domains, aliases, and forwards
When an E-mail message arrives on your VPS2, sendmail checks the incoming domain and determines
if it is either a local domain, or an authorized relay domain. In addition to the VPS hostname (or
primary domain), which is always considered a local domain, you can have any number of local domains
on your server. In order to be considered local, you must have the domain listed in the
/etc/mail/local-host-names file on your server. Once a domain is determined to be local,
sendmail checks the virtusertable
and then the aliases to determine if
there is any special delivery conditions for the recipient address.
Once an E-mail recipient has been checked against the virtusertable for domain based delivery, the
domain name of the recipient is ignored by sendmail. The username, without the domain, is then
checked against the aliases, and finally delivered to the correct local user's mailbox.
Your VPS2 can also be configured to relay E-mail messages from authorized domains. This allows you to
use your VPS2 as a secondary mail server. When an E-mail message arrives with a recipient domain that
is listed in the /etc/mail/relay-domains file, sendmail will try to deliver the message
to the primary server. If the primary server is unable to accept the mail, sendmail will hold
the messages in a special queue, and will deliver them to the primary mail server once the primary
server is online again. This feature is especially useful to companies using exchange servers, or who
have limited network access to their primary mail server.
Mail Filtering and SPAM prevention
In addition to recipient based mail routing, sendmail can be configured to filter or route
messages based on other elements of the message. The easiest way to do this is with
Procmail, an easy to configure mail filtering
add-on. You can also configure sendmail itself for filtering using the
M4 macro set.
While there are many possible reasons to filter mail, one of the most common uses is to
prevent SPAM (or UCE)
Other Popular E-mail Tools
There are a number of additional e-mail tools that you can configure for your VPS2. Some of the more
popular ones include E-mail list Managers,
E-mail message encryption, and
E-mail Automatic Reply.
Using Remote Mail Clients
For VPS2 users with Mail permissions, POP and IMAP compatible remote mail clients can be used to
download and send E-mail messages. For more information, see
Configuring E-mail Clients.
Additional Information
|
