Managing a Postfix Queue – Commands

Show messages in queue: postqueue -p

Display message: postcat /path/to/postqueue/messageID

Delete a message: postsuper -d (queue ID)

Delete ALL messages: postsuper -d ALL

Attempt delivery of a message: postqueue -i (queue ID)

Attempt delivery of all mail queued for a particular site: postqueue -s (site)

Attempt delivery of all messages (flush): postqueue -f

Put mail “on hold” (stop delivery attempts): postsuper -h (queue ID)

Release mail that was put on hold: postsuper -h (queue ID)

Show various postfix queue stats: qshape
More on qshape


Adjust Scalix Webmail Attachment Size Limit

Set attachment limits in Scalix

Scalix webmail

Can I limit the attachment size for messages prepared in SWA? Sure.
From the Scalix Wiki:

Scalix 11.x

  1. Navigate to /var/opt/scalix/nn/webmail directory on the Scalix server, where the file exists.
  2. Open the file with any editor.
  3. Near the top of the file, locate the parameter “maxAttachmentUploadKilobytes”. By default this is set to 10240, which equates to 10MB attachments. Modify the value appropriately and save the file.
  4. Restart scalix-tomcat.

Scalix 10.x

  1. Navigate to /etc/opt/scalix/webmail directory on the Scalix server, where the file partner.xml exists.
  2. Open the partner.xml file with any editor.
  3. Near the top of the file, locate the parameter “maxAttachmentUploadKilobytes”. By default this is set to 10240, which equates to 10MB attachments. Modify the value appropriately and save the file.
  4. Restart Tomcat.

PGP Encryption – Enigmail in Thunderbird email

Enigmail is a security extension to Mozilla Thunderbird and Seamonkey. It enables you to write and receive email messages signed and/or encrypted with the OpenPGP standard.

PGP Encryption - Enigmail automatically decrypts and verifies your Email





To install and configure Enigmail:

1) Install GnuPG

2) Find the appropriate Enigmail package, download and install

3) Create your Keypair

4) Set up ‘Per-Recipient Rules’. This will allow you to automatically sign and/or encrypt mail to specific people (or based on other rules). Just go to ‘OpenPGP’>’Edit Per-Recipient Rules’

Thanks Chris!


Scalix – Shared folders in IMAP clients

How to set up shared IMAP folders on your Scalix Mail server

Scalix webmail - Change your Scalix IP address

To allow IMAP clients such as Mozilla Thunderbird or Outlook Express to see the shared folders of users on a Scalix server, there is an additional step required.
First, set the permissions of the folders using Outlook or Web Access whilst logged on as the sharing user.

Next, telnet to the IMAP port on the mail server. You must login as the account that is to see the shared folders.
telnet 143
LOGIN yourname yourpassword
x-add-other-user otherusername

The command to remove them from your view is x-delete-other-user

Restart Thunderbird to see the change.

Originally, the instructions also said you should set permissions via IMAP on the user who is sharing the folder, but I don’t think its necessary, as that is covered by what you do in SWA or Outlook….for reference….

As user support login via IMAP….
setacl <foldername> <userid> <permissions>
setacl INBOX ian rs
allows user to access the INBOX of support with set permissions.

Permissions are as follows…
l - lookup (mailbox is visible to LIST/LSUB commands)
r - read (SELECT the mailbox, perform CHECK, FETCH, PARTIAL, SEARCH, COPY from mailbox)
s - keep seen/unseen information across sessions (STORE SEEN flag)
w - write (STORE flags other than SEEN and DELETED)
i - insert (perform APPEND, COPY into mailbox)
p - post (send mail to submission address for mailbox, not enforced by IMAP4 itself)
c - create (CREATE new sub-mailboxes in any implementation-defined hierarchy)
d - delete (STORE DELETED flag, perform EXPUNGE)
a - administer (perform SETACL)

Originally found at


Installing HylaFAX on CentOS 5

HylaFAX is an enterprise-class system for sending and receiving facsimiles as well as for sending alpha-numeric pages.

The software is designed around a client-server architecture. Fax modems may reside on a single machine on a network and clients can submit an outbound job from any other machine on the network. Client software is designed to be lightweight and easy to port.

Here’s a quick guide for installing HylaFAX on a CentOS 5 server:

1) Install dependencies:

yum -y install ghostscript sharutils

2) Get the RPM and install it:

rpm -Uvh /var/ftp/hylafax-4.4.4-1rhel5.i386.rpm

3) Start the hylaFAX config process: /usr/sbin/faxsetup

4) Accept defaults, except where info specific to your setup is necessary (area code, serial port for modem, fax number, company name, etc.). Replace ‘’ by the email address where all status messages will be received by HylaFAX. This enables the system status monitoring:

Should an entry be added for the FaxMaster to /etc/aliases [yes]?
Users to receive fax-related mail [root]?

In the last three lines here, we need to assign user rights. If you don’t want to assign user rights, use 644, 644 and 666:

Protection mode for received facsimile [0600]? 0644
Protection mode for session logs [0600]? 0644
Protection mode for ttyS0 [0600]? 0666

A the end of the config, say no to finish:

Should I run faxmodem for each configured modem [yes]?

5) Add usernames. To add users without passwords, use:

/usr/sbin/faxadduser username

or with passwords:

/usr/sbin/faxadduser -p password username


6) Edit vi /etc/inittab for the modem automatic answer. At the end of the file:

# Run faxgetty in runlevel 2 and 3
t2:23:respawn:/usr/sbin/faxgetty ttyS0

7) To setup fax send/recieve, edit /var/spool/hylafax/etc/FaxDispatch. On the 7th line change ‘FaxMaster’ to the email address you will use to send and receive. Directly under that line, you can add


to enable sending/receiving faxes as a .pdf attachment

8) Disable page chopping to insure full pages will be sent. Edit /etc/hylafax/hyla.conf and remove the comment from the Page Chopping line.

9) Restart the server, should be ready to fax!

taken from