Abstract
SMTP stands for “Simple Mail
Transfer Protocol”. An SMTP server allows you to send
internal and external mail through it. If your server is
referenced on the Internet public DNS as an MX
server for your domain name, then it also receives and manages
mail from the Internet addressed to users of your domain. This wizard allows you to setup a mail server with
Postfix.
The first step consists of choosing whether you intend to use an external SMTP relay or not. If you can use one provided by your ISP then choose Relay mail server in the drop-down list. Otherwise, choose Main mail server. In the procedure below only the second step differs from one configuration to the other.
Global Postfix Configuration
Relay (for Relay mail server only)
This is where you define the mail server responsible for relaying your outgoing messages.
What destination domains (and subdomains thereof) this system relays mail to. Mails sent to a domain other than the local domain that are not part of the relay domains are rejected (to prevent spam).
Main server Configuration (for Main mail server only)
For security reasons you might require remote clients to identify themselves before starting communication. Choose yes in this case.
The verify
command can be used
by a client to verify a specific user is actually
handled by a mail server. You can disable it to prevent
email harvesting by spammers.
This field
is used to masquerade the domain from which internal
mail appears to come from. For example:
foo.example.com example.com
directs
Postfix to masquerade
toto@foo.example.com
to
toto@example.com
.
Message options
A few options affecting message handling you can leave at their default values.
If a message cannot be delivered after this delay
it is sent back as undeliverable. Expressed as a number of days prefixed by the letter d
, for example 3d
means three days.
Messages larger than this size (kilobytes) are rejected. When defining this parameter, please bear in mind that binary attachments have a bigger size than their filesize because they have to be encoded differently to be sent in a mail message.
If a message cannot be delivered, the sender will receive a warning after this number of hours.
Network Configuration
The network interface addresses that this mail
system receives mail on. By default the server listens on all network interfaces (all
), specify localhost
to listen only on the local interface.
The list of domains that are delivered via the local mail delivery transport. The SMTP server validates recipient addresses and rejects non-existent recipients.
The list of “trusted” SMTP clients who have more privileges than “strangers”. In particular, “trusted” SMTP clients are allowed to relay mail through Postfix. Specify a list of network addresses or network/netmask patterns, separated by commas and/or whitespace.
If a parameter is not clear to you, please refer to the Postfix Configuration Parameters.