Chap 7: Local Delivery and POP/IMAP

Question 1

What are the 2 types of message formats managed by postfix ?

Answer 1

Mailbox (mbox) and Maildir

Question 2

What is the difference between Mailbox and Maildir ?

Answer 2

Mailbox adds all emails of a single recipient in a single file. It is fast, however it requires to manages locks to sync with other processes accessing that file.

Maildir add all emails in separate files in a directory structure including the directories new, cur an temp.

Question 3

what is the purpose of the parameter local_recipient_maps ?

Answer 3

Lookup tables with all names or addresses of local recipients. A recipient address is local when its domain matches $mydestination, $inet_interfaces or $proxy_interfaces. Specify @domain as a wild-card for domains that do not have a valid recipient list.

Technically, tables listed with $local_recipient_maps are used as lists: Postfix needs to know only if a lookup string is found or not, but it does not use the result from table lookup.

Question 4

What is the purpose of a .forward file ?

Answer 4

.forward files allow local users to set up their own aliases. The contents of the .forward file are the same as the righthand side of an alias entry.

Question 5

Where are the .forward files located ?

Answer 5

.forward files must be owned by the recipient, and are normally found in users’ home directories. You can specify different locations with the forward_path parameter.

ex:
forward_path = /home/$user/.forward /home/$user/other_forward

Question 6

Which parameter allows to change the default location of the mail spool directory ?

Answer 6

mail_spool_directory

Question 7

How to choose the maildir format for mail boxes ?

Answer 7

Specify a name ending in / for maildir-style delivery in the parameter mail_spool_delivery

Question 8

How to deliver mail into home directories ?

Answer 8

Assign a relative path to the home_mailbox parameter to indicate which file should be used for
mailboxes:

home_mailbox = mbox

Append the path with a trailing slash to indicate that Postfix should use the maildir-style
delivery:

home_mailbox = maildir/

Question 9

What means LMTP ?

Answer 9

Local Mail Transfert Protocol

LMTP is based on, and is a simplified
version of, SMTP