Post.Office 3.5, by Tenon Systems
Posted: 27-Nov-2005

3 out of 5 Mice

Vendor: Tenon Systems Type: COMMERCIAL

Reviewer: Bill Catambay Class: INTERNET

Post.Office is a scalable SMTP/POP3/IMAP messaging server designed to meet the needs of small and mid-sized ISPs, but can also be used by hobbyists running their own servers on Mac OS X. Post.Office can support 10 users or ten thousand users on a single platform with appropriately configured hardware. Post.Office provides web forms for administering the server and accounts, and also includes options for setting up mailing lists. System administrators can make changes from anywhere on the Internet using the web forms. Postmasters can use Post.Office to easily administer enterprise email systems. End users can specify how their mail should be handled, join mailing lists, and manage mailing lists.

For years, the Mac Guild has maintained mailing lists on its own
Avalon server use the EIMS mail server. In combination with EIMS, we have used a freeware list server called Autoshare. Our server recently upgraded from Mac OS 9 to Mac OS X, and while there is a Mac OS X version of EIMS, Autoshare remains a Mac OS 9 application, and support of Autoshare has pretty much evaporated. Post.Office provides a single package that includes a mail server as well as mailing list software which runs native on Mac OS X. This review is of Post.Office running on a Mac Mini under Mac OS 10.3.9. For the intent of this review, we will set up accounts and mailing lists in support of the current MacSurvivor contest.

Vendor Listed Features

  • Provides uncomplicated, user-friendly interface for its basic operating functions
  • Post.Office does not run with 'root' privileges and operates independently of the host computer system, making it virtually impossible to compromise the main system security via the email program
  • To curb the proliferation of SPAM, Post.Office offers SMTP mail relay protection, including POP before SMTP, to restrict the system and/or users who may try to use the ISP's email server to relay messages. Post.Office also includes powerful header and body message filtering, and Dynamic Relay Black List support
  • Post.Office can be instructed to issue a pre-set, automatic reply to senders, returning the incoming message or any chosen message as instructed
  • Post.Office allows quick creation and easy administration of thousands of mailing lists for groups of users to share information on common topics
  • Post.Office offers a variety of configuration options to more efficiently manage system resources, including administrator-definable limits and parameters for a number of system level processes
  • Post.Office can be used with WEBmail to give your server powerful web-based e-mail capabilities


  • Mac OS X
  • Connection to Internet or Intranet


$295 (100 mailboxes plus 10 mailing lists)

Post.Office can be purchased as a download, or on CD. I downloaded the software, and ran the installer program. The installer requires admin authentication, and then installs a daemon process for the mail server, and installs the Post.Office application on your hard drive. By running as a daemon process, the server is automatically active each time the system boots, and the Post.Office application does not have to be running. The Post.Office application is a very simplistic window for a few initial settings to get your server running properly. You need to setup your local domain and a password for the root administrator. This is where you would enter your license code as well. It is not the most easy to understand dialog, but the good news is that you only have to do this once. The rest of the administration is performed on the web.

Remote Management
Once the server is up and running, configuring and managing the server is done within a web browser. You can do so on the server itself using the URL, or remotely on another computer using the server's IP or DNS address. For this review, I performed all of the configurations from a remote computer, and so the primary URL I used for administration was

When accessing Post.Office via the web, you are prompted for an id and password. If the id is an admin id, you gain access to the administration tools. If the id is an end user account, a simpler web page is displayed for end user support.

After accessing as an administrator, you arrive to a web page with 5 primary functions: Account Admin, Mailing Lists, Deferred Mail, System Config, and Help. Within each primary function, there are several functions that can be performed.

Before setting up accounts and mailing lists, I first went into the "System Config" function to review and adjust server settings.

Post.Office System Configuration

System configuration allows you to establish SMTP aliases, set your mail routings, restrict mail relaying, and many other SMTP settings. Establishing these settings are important, especially if you don't want your mail server blacklisted as a server that relays spam. Most server admins understand what most of these settings are used for, but if there are any questions, you can click on the "Help" button for detailed explanations.

Email Accounts
Post.Office supports POP and IMAP email accounts, all which can be managed using the Account Admin button.

Post.Office Account Admin

Under Account Admin, you can view a list of accounts, create a new account, or edit the default information used for creating new accounts. This page also includes a quick search form to look someone up without having to browse the accounts. When you click on "List of Accounts", you are presented with a method of selection which turns out to be quite common throughout Post.Office. You are given a stream of letters. from A to Z, with the option to select "All". Given the few accounts I setup for testing, I found that I always clicked on "All". Given how often I was doing this, it would have been nice if there was some way to tell Post.Office to default to "All" when I clicked on the "List of Accounts" parent link. From the list of accounts, you can view and manage existing mail accounts.

To create a new account in Post.Office, you click on the "Create New Account" link. From there, you are presented with a list of account options, starting with the account name. Accounts can be created as POP or IMAP, and various privileges and/or limitations and restrictions can be set for each account. If you find that you are changing many of the settings the same way for each account you create, you can streamline that by first going to the "Edit Default Account Data" link. There you can set the defaults so that when you do create a new account, most of your settings are already in place. This is a good time saver.

End User Account Management
There are two levels of administration for email accounts (as well as mailing lists). The server admin has privileges for creating and deleting the accounts, as well as setting the account types and other privileged settings. End Users, on the other hand, are provided some simple privileges for adjusting their account settings. What type of access you are granted depends upon whether you logged in with an admin or an end user account.

End User Account Management

By accessing the Post.Office server IP address, end users can remotely update their own account settings. This is a great feature, allowing users to adjust settings that they might otherwise have to contact the administrator for. End user account management includes the functions of changing your password, changing your delivery method, setting up a vacation message, editing personal information for Finger and Directory lookups, and viewing information about the account.

Mailing Lists
In addition to email accounts, Post.Office includes the feature of setting up automated mailing lists. When setting up a mailing list, various email addresses are subscribed to the mailing list, and Post.Office handles the email distribution when a post to the mailing list is accepted.

The Post.Office administrator can create, edit, and delete mailing lists by clicking on the "Mailing Lists" button.

Post.Office Mailing List Administration

Similar to the Account Admin page, the Mailing List Admin page allows the user to view a list of mailing lists, create a new mailing list (in either short form or long form), and edit the default settings for a mailing list. This page also includes a quick search for looking up a specific mailing list.

Clicking on the "List of Mailing Lists" link brings up the alphabet letters again, including the "All" option. Clicking on "All" will retrieve all of the mailing lists on that server. From the resulting list, you can then click to delete a list, view a list, or edit a list.

When creating a mailing list, you establish a number of primary settings which are included in both the short and long form. These settings include the name of the list, a short description, the primary mailing list email address, additional list addresses (such as aliases), and the list owner email address. If you establish data on the "Edit Default Mailing List" page that can be used for all your mailing lists, then the short form is all you really need to use. The long form provides additional information that can be set for a specific mailing list. This includes welcome and farewell messages, a longer description, header and footer text to include in each post, email header options, whether the list accepts digest subscriptions, and many more.

One of the problems I ran into occurred when I tried to assign a email address as the list owner for a mailing list. I learned that Post.Office only accepts list owners that are Post.Office accounts on that server. The work around for this issue was to create an account on Post.Office, and having it automatically forward to the address. Although there is this work around, it seemed unnecessary. It would be better (and easier) if it accepted a list owner from any domain.

Errors and Deferred Mail
The Mailing List Admin page includes a link for "Deferred Mail" which provides different options for deferred mail and error messages. You can view the error messages currently held for action, set preferences for error handling, view email currently held in queue, and set mail queuing options. Post.Office is very versatile in terms of setting up and managing error conditions and held mail.

Post.Office Deferred Mail page

End User Mailing List Management
For non-administrators, there are some useful functions provided on the web for managing your mailing lists. These can be pulled up by clicking on the "Mailing Lists" button on the End User page.

End User Mailing List Management

The Mailing List Management page provides options for viewing the available mailing lists, managing lists that you own, and subscribing or unsubscribing to a mailing list.

Post.Office Mailing List Directory

When viewing the list of mailing lists, you can see which lists you are subscribed to. Clicking on the mailing list link brings you to the list summary page where you can view your settings and subscribe or unsubscribe. The page also displays information about the list. In addition to the list summary page, another method for subscribing is using the "Subscribe to Lists" link from the list management page. This link will display a list of all mailing lists you are not subscribed to, and allow you to subscribe to multiple lists in one operation. Similarly, the "Unsubscribe from Lists" link will display a list of mailing lists you are subscribed to, and allow multiple unsubscribes. There is no way to change subscription types (aka, digest vs immediate) for multiple lists. There is also not any option for changing your subscription to "Suspend" to temporarily suspend mail delivery from the list, nor is there a way to specify Ack versus No-Ack (where Ack means receiving your own post when you post a message to the list). By default, you receive your own posts in addition to posts by others. Suspend/Resume and Ack/No-Ack are common mailing list options found on other mailing list servers. They are noticeably absent from Post.Office.

Post.Office Interface
Post.Office is filled with features and options that allow anyone running Mac OS X or Mac OS X Server to setup a viable email server, including options for mailing lists. It provides the basic functionalities of a mail server and list server, with a lot of options for customization. Over several weeks of use, both the mail server and list server operated without any problems. The throughput was quite reliable.

The web interface, however, is not without its quirks. The details of the interface began to show signs of confusion over extended periods of use. The more I used the web interface, the more frustrated I got with it.

One big problem is navigation. I often found myself on a page with no clear link to return to where I was. An example of this is when you click on the "i" (information) links. These links do not open in a new window or a frame, but completely replace the contents of the entire web page, and provide no links back. Having to rely on the browser's "back" button is not good web page design.

Probably the biggest non-intuitive feature of Post.Office are the error messages. I received several errors during my testing, and more times than not I had no clue what the message was trying to tell me. For example, when trying to create a mailing list, I received the following errors:

An error occurred when processing one of the fields on this form:

Please correct the field and try again.

An error occurred when processing one of the fields on this form:

Please correct the field and try again.

I found these messages to be cryptic at best, leaving a lot of burden on the administrator to decipher them. The messages above mean that a list owner email and list manage email address need to be specified. All of the Post.Office error messages are in this same cryptic format. Not at all useful when trying to resolve issues.

The interface also suffered from tedious non-intuitive behaviors. When creating a list, there is a "List Owner Alias Addresses" and "List Owner Address". When I specified a List Owner Address, I still get the "ListOwner-SMTP-Address is in error" message. If I specify an alias address and leave the other email blank, that error goes away. I wasn't sure how to get rid of the ListMgr-SMTP-Address. When I specified an email for List Request Address, the error changed to:


I finally realized that I had to specify a List Owner Address that was a local email address. The error messages did not help me at all in arriving to the understanding.

After creating a list, I had expected to be presented with a page that would allow me to quickly add some subscribers. Instead, I was returned to the Mailing List Admin page. From there I had to first click on List of lists, then find the list I just created, then click on Edit Subscribers. I pasted in a list of email addresses separated by commas, but for some reason, only one email address was accepted (and then I was returned by to the main admin page again). I wondered why this occurred, so when I went back into that page, I clicked on the "Info" icon, but that led to a blank page that said "Unknown Help". Through trial and error, I found that by removing the commas and instead pressing return after each entry, all the entries were accepted. When entering in multiple email addresses to fill up the subscriber input field, there were never any scroll bars activated so that I could scroll through the list. If you put in more addresses than can be viewed in the box, you have no way to see what they are.

Editing subscribers was also a little awkward, since you couldn't click on a subscriber to edit or delete; instead, you had to add a subscriber as new, or enter the subscriber email address in the Delete input box to delete one.

After adding subscribers, I noticed one missing, so I tried to add it. The web page said it was already added, yet it was still not showing up in the list of subscribers. Strangely, there was one showing that I never even entered. I tried to delete the mystery address, but even though it accepted the delete command, when I went back into the list, it was still there. I then deleted the email address that I originally added (but wasn't showing as being subscribed), and the action caused the erroneous address to be deleted. At that point I tried to re-add the correct email address, but it then changed it to the erroneous email again. The one I entered was, but the one that kept showing up was (which is the server domain). There is a that exists on Post.Office, and it has an "Additional Email Address" of, but I see no reason why Post.Office keeps swapping it in the subscriber list. I finally decided to just delete the account so that the list would accept the email address.

When clicking on list of mailing lists, you always default to lists starting with "A". I couldn't find a way to have the page default to all lists (which is more practical). What makes this worse is that when you're done viewing or editing a list, instead of returning to the list of lists you were looking at, you return to the mailing list home, and have to click on lists, and then click on "All" again. Seemed like a lot of repetitive clicking to get around.

The web interface is also missing a logout button. I wanted to switch from user mode to admin mode, but could not find a way to logout on the web page. I had to close the browser and then re-open it to logout.

Noticeably missing from Post.Office is a mailing list archive. That seems like a standard mailing list feature, one that most lists really need, so I was surprised to see the feature missing.

I found switching a user from digest to immediate was needlessly difficult. Using the Admin Management, the only way to switch their preference was to delete their old subscription, then resubscribe them with the new option (digest or immediate). Even as normal user, once you are already subscribed, clicking on "subscriptions" you will not see the list. The only way to switch from digest to immediate or vice versa is by unsubscribing and then re-subscribing.

Post.Office, once installed, runs as a daemon process, so you don't have to worry about starting it up each time the server boots up, nor do you even have to specify for it to start in your login startup items. It automatically starts when the machine boots. This is a very nice feature. Unfortunately, not a lot was done to provide for an uninstall option. There are no instructions for uninstalling in the installation guide, but I did find some information in the
online FAQ. The FAQ discussed using a number of Terminal commands, or an uninstaller script. The uninstaller script did not work for me, so I had to use the following Terminal commands to uninstall Post.Office:

sudo rm -R /usr/local/
sudo rm -R /var/spool/
sudo rm -R /Library/StartupItems/PostOffice
sudo rm -R /var/spool/mailbox
sudo rm -R /Applications/
sudo rm /etc/
sudo rm /usr/lib/libPO35.A.dylib
sudo rm -R /Library/Receipts/Post-Office.pkg

Post.Office comes with a good deal of useful documentation. You can click on the "Help" link on the web interface to pull up the documentation, or you can access it from
Tenon's web site. Tenon provides a Post.Office Admin Guide, a Post.Office Users Guide, a List Owners Guide, and an Installation Guide. In addition to the user guides, there is also the Post.Office FAQ, as well as a Post.Office mailing list. Although the user guides are available on the web interface, I strongly recommend downloading them externally. The problem with the web interface is that while you are browsing the PDF, your session can expire (like it did on me), and then you are tossed out (even though you are only reading the manual).


Tenon's Post.Office is a highly stable mail server for Mac OS X that supports SMTP, POP and IMAP. Post.Office also incorporates a built-in mailing list server. Account and list management is all done on the web, and can be done from any computer that can reach the server. I found the server software to be quite dependable for running some mailing lists for our MacSurvivor contest. There are many interface and navigation issues that can be improved in Post.Office. Error messages rarely provide any useful information, and moving around and performing repetitive tasks could be greatly improved. Post.Office is also void of a list archive feature. While Post.Office provides a very decent product, it is missing features and ease-of-use which can be found in EIMS (mail server) and Autoshare (list server only runs in Classic mode). If you don't have a need for list archives, and don't mind the interface quirks, the server software itself is powerful and reliable. For a rock solid combination of a mail server and list server package that runs native in Mac OS X, Post.Office is definitely worth a look.


  • Stable and reliable email server
  • Built-in mailing list server
  • Remote administration via the web
  • Lots of customization options
  • Good documentation


  • Cryptic unhelpful error message
  • Tedious and non-intuitive navigation
  • Painful uninstall process
  • Only allows mailing list owners who have local accounts on server
  • No mailing list archives

Overall Rating:

3 out of 5 Mice