Official announcements from either or David Harris.

David Harris posted Sep 6 '11 at 8:15 am

September 5th 2011: Pegasus Mail v4.62 now available for public distribution

Version 4.62 mainly concentrates on fixing late-breaking

incompatibilities in HTML rendering caused by the release version of

Microsoft's Internet Explorer 9 browser. V4.62 users should experience

reliable, high-quality HTML display using this version, with the quality

of rendering being even higher than in previous versions.

  • Updated editor  V4.62 also uses a heavily-updated version of

    the editor module we use, and has numerous changes in the way editing

    buffers are constructed, meaning it should now be able to edit and reply

    to much more complex HTML message formats than previous versions, and

    editing should be much more reliable.

  • Open link in background   You can now Ctrl+Click on any link

    in a message to open that link in your web browser without bringing the

    browser to the foreground. This allows you to open a succession of links

    then work with them when you're ready.

  • Signatures overhauled   The way signatures are handled has

    been totally overhauled, and you should now find they work considerably

    better when you insert them at compose-time.

  • Faster POP3 downloads   POP3 downloads should be significantly faster when you have chosen to leave mail on the POP3 server.

Finally, quite a few small bugs, some of them quite long-standing, have now been fixed.

We expect this to be the last release in the V4 family of Pegasus

Mail, with the next release being the first iteration of the V5 family, which we plan to release in a staggered pattern to ensure more regular updates.

I apologize to everyone for the length of time it has taken to get v4.62 out the door - many of the changes it required were quite subtle, and testing has taken a lot longer than we initially expected. I am trying hard to adjust the way development is conducted to allow more regular releases to be made, and hope you will bear with me in the meantime.


-- David --

David Harris posted Apr 1 '11 at 2:21 am

Mercury/32 v4.73 has now been released. This new version contains significant new capabilities and a number of important fixes, especially for the MercuryI IMAP server.

V4.73 is the final iteration in the series of incremental upgrades to

Mercury v4.7 that has come out since its release, and will be the last

release in the v4.x family, with development proceeding to Mercury/32 v5

from this point on. We hope to release V5 sometime in 2011.

The following changes are present in v4.73:

  • Selective SSL options  The MercuryS SMTP

    server now has options that allow you to enable SSL support on the

    primary and alternate SMTP ports selectively (so, you can have SSL

    enabled on the secondary, but not on the primary, ideal for submission

    by your remote users). There are also new Access Control permission

    settings in the MercuryS ACL editor that allow you to enable or disable

    SSL based on the IP address of the connecting client.

  • ACL range corrections  In previous

    versions of Mercury, access controls would not work correctly if the

    address range exceeded 256 addresses, and would occasionally work

    incorrectly with particular address ranges. These problems have now been


  • Duplicate message suppression  You can now

    create an empty file called MSGIDS.MER in any mailbox directory (i.e, a

    directory where a .CNM file gets created), and this signals to Mercury

    that it should suppress duplicate messages in that mailbox. Duplicate

    detection is based on a combination of sender and message-ID, and only

    the last 200 messages delivered to the mailbox are actually remembered.

  • MercuryC forced sender option  This option

    allows you to specify a single address MercuryC should use as the

    source of the mail it is sending when it is negotiating with the

    upstream "smart host". This option is quite technical, being buried in

    the depths of the SMTP transaction itself, and does not affect the

    "From" field in the message, or alter the contents of the message in any

    way, other than altering the Return-Path header that the smart host

    will write into the message. It is primarily aimed at users of services

    such as Yahoo Premium Mail, which require the SMTP "MAIL FROM" address

    to be the address of a known subscriber.

  • Extended POP3 lockout detection  MercuryP

    now locks out any account with too many login failures for five minutes

    regardless of the address from which the lockout occurred. So, once any

    system has failed logging into a POP3 account, all systems are prevented

    from attempting to login to that account for five minutes. This feature

    is primarily aimed at botnets that attempt to crack passwords by

    logging in from successive different systems and trying

    username/password combinations until they fail, and is automatic.

  • Fixes for MercuryI IMAP  MercuryI now

    saves UID lists any time they change: this should prevent UID

    synchronization problems from occurring, but may introduce small extra

    processing delays with very large folders. There have also been some

    changes in the way the IMAP SEARCH command is handled that should

    improve performance and reliability in a number of search scenarios (in

    some cases spectacularly), and MercuryI now caches FETCH data which

    should significantly improve performance and reduce load when clients

    like Apple Mail fetch messages a chunk at a time.

  • MBXMAINT updated  The mailbox maintenance

    utility MBXMAINT has been heavily updated. It now fixes a wider range of

    problems, and can also correct folders where messages contain duplicate

    message identifiers (important for more reliable IMAP operation). The

    program has been split into a commandline version, MBXMAINT.EXE and a

    user-interface version, MXBMAINT_UI.EXE. Both versions have considerably

    better reporting and output.

  • Random filename generation fixed  A very

    long-standing problem where the "random" filenames generated by Mercury

    were not very random and tended to repeat has finally been found and

    corrected. Mercury should now generate much more "random" filenames and

    the possibility of filename collisions should be dramatically lower as

    of this version.

to go to the Pegasus Mail home downloads page and retrieve v4.73.


-- David --

David Harris posted Feb 24 '11 at 12:54 pm

Pegasus Mail v4.61 is now available for public download in English, German and Italian versions: the French version will be released shortly.

Version 4.61 is an interim release

– not quite version 5, but part of the way there. We're releasing it

primarily because it incorporates some important bug fixes, but it has

some extremely worthwhile new capabilities too.

  • New HTML renderer  HTML has

    become increasingly common in e-mail, even though it is actually not

    especially well-suited to the medium and is technically challenging to

    implement there. Version 4.61 includes a new HTML renderer that uses the

    built-in power of Internet Explorer to render HTML. Developed by

    Michael in der Wiesche, this renderer has been exhaustively tested and

    secured, and we believe it meets all our very high standards for

    security. For people who really don't trust Internet Explorer, though,

    Martin Ireland's BearHTML renderer has also been improved and can be

    used instead with a single click of a button.

  • New graphics, updated interface

     Version 4.61 sports beautiful new graphics designed by Sven Henze. The

    program is also most of the way towards a redesigned user interface with

    a more "modern" 3D look. We believe the combination of Sven's graphics

    and the new look make the program very attractive in a classical way.

  • Numerous bug fixes  including,

    but not limited to the following: HTML messages with very long lines

    will now render correctly; mailto: specifiers are now removed correctly

    when adding addresses to addressbooks and lists; fixed crashes caused by

    various types of malformed message; corrected the colour selector for

    filtering rules; allowed folders to be dragged onto closed trays when

    rearranging the folder hierarchy... and many more.

  • Accent expansion in the glossary

     you can now create accented characters using the Glossary Expansion key

    (Ctrl+E in the English version). Simply type the base character

    followed by the accent you want added, then press Ctrl+E. For example,

    to create an e-acute character (é) simply type e' then press Ctrl+E. For

    a complete table of the accented characters that can be created,

    consult the full Pegasus Mail help file.

  • Confirm-reading prompts  You can

    now have Pegasus Mail prompt you for whether or not a

    confirmation-of-reading message is sent when a message contains a

    request for one (the original options for always and never sending them

    remain available as well). Make this change in the "Advanced" settings


  • Size column for drafts and queued mail  The window that displays draft messages and messages in the sending queue now includes a size column, by popular request.
  • Attachment size controls  System

    administrators wanting to control the maximum sizes of attachments sent

    with the program can now do so by running the LIMITS.EXE program

    supplied with the system. LIMITS.EXE allows you to specify both soft and

    hard limits (a "soft" limit pops up a warning but still allows the user

    to add the attachment, while a "hard" limit does not allow the

    attachment to be added). LIMITS.EXE places values in the Windows

    Registry, and system administrators may wish to remove it from the

    installation directory to a location not accessible to users.

  • Commandline and GUI versions of MBXMAINT

     The Mailbox Maintenance utility, MBXMAINT, now comes as two versions:

    MBXMAINT.EXE is a commandline utility that can be used in scripts, while

    MBXMAINT_UI is the traditional GUI version of the application. Both

    have also been slightly improved in the types of error conditions they

    can handle.

to go to the Pegasus Mail home site downloads page, where you can find the v4.61 release.


Phons posted Feb 13 '10 at 4:00 pm

Hello community,

I've loaded up a nice '20th Anniversary of Pegasus Mail'-button Gold; spread and use them on your site and in your signature.

David Harris posted Jan 23 '10 at 2:01 pm

Pegasus Mail v4.52 is now available for public download.

V4.52 is all about allowing the program to work well under Windows 7: it can now use the new Microsoft mechanisms for registering itself as a system-level mail program (meaning it can be used to launch mailto: links from your web browser), and corrects a number of minor issues in previous versions, in particular the problem with some toolbar buttons either not displaying or displaying incorrectly. There are also some internal reliability fixes to do with the way certain types of folder damage are handled.

Producing a Windows-7-capable version of the program required migrating the Pegasus Mail source code from Microsoft Visual Studio 2003 to Visual Studio 2008: we expected this process to be easy and quick, but we were wrong - Microsoft made it much more difficult than should ever have been necessary. This is the main reason it has taken us as long as it has to get this release out the door. An unfortunate side-effect of this is that Visual Studio 2008 generates applications that cannot be run under Windows 98 or ME. As a result, v4.52 no longer works on these older versions of Windows. As I've noted in the information on the main Pegasus Mail site, we will see what we can do about putting together at least a matching version of v4.52 that *can* run under Windows 98 and ME, but it's clear that we are not going to be able to support these systems for very much longer.

Pegasus Mail v4.52 can be downloaded from the main Pegasus Mail web site, at : it will be made available here on the community as soon as humanly possible.


-- David --

David Harris posted Jul 3 '09 at 2:07 am

Pegasus Mail v4.51 is now available for unrestricted public distribution - please visit for downloads and information, or check the download pages here at the community. The release version has had significant work since the public beta at the end of last year, and has some powerful new capabilities, most notably the addition of autofiltering folders.

The release of v4.51 marks the end of one of the most difficult development periods in the history of the program, and it seems appropriate that it should coincide with my attempts to ensure the long-term survival of the package: from here, development should be both easier and faster, and I do not anticipate ever again having such a long delay between releases. Your assistance is crucial to making this happen though, and if you haven't already done so, I would ask that you read the open letter at the main web site and see if you are able to help. To all of you who have already pledged your support, I offer my sincere thanks.

No version of Pegasus Mail has ever been as extensively or exhaustively tested as v4.51 - it's been a huge job, but ultimately rewarding, and my test team and I hope that you really enjoy using it.


-- David Harris --
July 3rd 2009.

David Harris posted May 26 '09 at 11:22 am

A release candidate for Mercury/32 v4.71 is now available at . We intend to make this available only at the community site for a week or so before releasing it on an unrestricted basis.

The big news in v4.71 is the ability to run as a native Windows Service: we (the test team) have been using it extensively in this mode for quite some time and it's really quite cool. There are quite a few other small new features in there, and over 200 fixes and corrections.

Feedback is welcome in the Mercury beta forum here.


-- David --

PiS posted Feb 15 '09 at 1:13 pm

Wiki On-Line
Today we welcome you to the all new pmail Wiki!

A Wiki is an on-line documentation repository, where you can contribute. The wiki supports both Pegasus Mail and Mercury MTA, and it is multilingual. Try it out at

For a while there has been a wish to be able to extend the documentation of Pegasus Mail and Mercury Mail Transport Agent, plus concentrate information from various sources into one general repository. Today we proudly invite all users to contribute into creating the definitive guide to e-mailing in general, and about how the programs work in particular. All this will during 2009 be concentrated to

In short time the knowledgebase documentation will be transferred onto the wiki, as well as the official software documentation, including help subsystems and development guides. Currently the closed beta team members concentrate in their free time on merging the documents, but this is a vast task. Pegasus Mail exists in several languages, but Mercury does not. Translation has always been a rather gigantic task. Both programs are used all over the world. therefore supports multiple languages, and you are all encouraged to pitch in and extend the documentation into your language.

Developers of daemons and extensions are most welcome to publish their how-to guides and accompanying documentation in this one place repository.

The basic idea of a wiki, is that anyone can suggest and contribute to completing the information. Seldom are the ones with deepest information equiped to write guides on how to use things, as the users themselves. At anyone can add, correct or extend the information so that it is as comprehensible and complete as can be.

For those not so familiar with wikis, you may want to look at the original site and you'll find a world of information. We have built according to the same syntax, and on the same platform - to ease the use and contribution, and it is our hope that the pmail wiki will be of benefit to you all. The wiki contains a sandbox, were you can familiarize yourself with editing and contributing.

PiS posted Dec 8 '08 at 12:11 am

Community.Pmail.Com now has native support for the following languages, Dutch, French, German, Italian and Swedish, besides English.

We have also added international Community support forums in Dutch, French, German and Italian. The aim is to make a natural point of interest and a global repository of information regarding the products: Pegasus Mail and Mercury Mail Transport System.

To enable your preferred languague, you have to set your language in your profile. Your profile is reachable by clicking your name, which is displayed at the top right of all community pages.

We've also made some minor changes to the forum names, and merged some quite similar forums into more obvious forums.

It is my personal hope that you find this change easier and more appealing in your use of the forums.

Pmail.Com posted Sep 3 '08 at 3:58 pm

Downloads are now available from the community.

Pegasus Mail Public Beta v4.51 (German)

Please use the Beta forum for any discussions regarding the beta versions.
Forum posts will be moved when they relate to the beta and have been published in the wrong forums. We are aware that moving forum threads creates trouble for those that keep up with unread posts, so please adhere to this policy.

David Harris posted Aug 4 '08 at 3:15 am

As many of you have noticed ( <wry grin> )  the time between releases has in recent years been getting longer and longer, both for Pegasus Mail and Mercury.

The long period between releases does not, however, mean that nothing is happening: there are numerous reasons for the longer development cycles, many of which I have covered in my blogs, and in the background, there are many, many releases of beta versions of the program that are only ever circulated to members of the current closed beta test teams. To give you an example, there have been 22 formal betas of Pegasus Mail v4.5, and numerous informal betas where I wanted to try out a specific feature.

After consultation with my closed test teams, we've reached the conclusion that the community and the quality of the programs would be best served if we opened up the beta testing process: making betas available publicly would allow wider testing, as well as giving a clear, visible indication that the programs are alive and in active development.

Accordingly, after the release of Pegasus Mail v4.5 (which will be very soon now - we're testing release candidates at present), I will be opening the beta process. Most betas will be made publicly available on this community for both programs, and forums will be provided for feedback. Betas will be provided without support, typically will not include installers, and will be intended to be installed only by experienced users.

Watch this space for further announcements.


-- David --


UPDATE - 30 July 2008: Top marks to Ironport - they got onto me very rapidly and have been extremely helpful. It now appears that this problem is a combination of an ISP who is blacklisting his own netblocks (doh!), and a slightly ambiguously-worded error response from the Ironport appliance involved. It appears at this stage that the problem is an isolated occurrence, and that there is no cause for concern. But I want to reiterate how wonderful it is to encounter a large vendor this responsive - excellent work, Ironport.

----------------------------- Original posting below -------------------------------------

It's been brought to my attention that a large company that develops anti-spam mail server appliances, Ironport (, may have begun rejecting mail sent by Pegasus Mail because it erroneously believes Pegasus Mail is a spam generation program. [:(] [8o|]

We're still investigating this and will keep you informed, but for now, if you find at any stage that you get a mail message returned to you with a 554 diagnostic that talks about your message not being accepted because of the "poor reputation of the MTA" you're using, please let us know on the forums.

If anyone here knows how to get in touch with Ironport Systems (their web site is essentially purely a marketing site and has no technical value), we'd also be very grateful if you could let us know.

-- David --

David Harris posted Jul 3 '08 at 8:53 am

A new kit for the development of Mercury/32 Daemons (or plugin processes) is now available for public release from our web site. This kit allows programmers to create Daemons that integrate tightly into the Mercury environment, extending its capabilities. As examples, the SpamHalter, GrayWall and ClamWall plugins shipped with Mercury are all Daemons.

For more information on the Mercury/32 Daemon Development Kit, please visit our web site at .


-- David --

David Harris posted Jul 3 '08 at 8:52 am

Mercury/32 V4.62 is now available for public release.

V4.62 fixes a problem in v4.61 where sites who had not turned on the new "DST-Proof UID" feature in the MercuryP POP3 server could get duplicate message downloads under certain circumstances. It also includes some adjustments to the installer program during upgrades, and has some minor internal changes to the Daemon interface for future development.

Mercury/32 v4.62 can be downloaded from our official download pages, at .


-- David --

David Harris posted Jun 22 '08 at 5:07 pm

Mercury/32 v4.61 has now been released for public consumption - please visit for more information and downloads.

I apologize for the rather delayed release - we've had a very frustrating sequence of last-minute problems come up, all of them fairly small, but significant enough to justify holding the release while they were fixed.

The new feature list for this release appears at the end of this message.

Cheers to all!

-- David --


V4.61 includes a large number of minor fixes (over 300

by our count), and some notable new features:

  • Notifications and alerts

     If you purchase (or have already purchased) a

    license for Mercury, you can now enable automatic checks

    for new releases and updates, security bulletins and

    general information about the program. To take advantage

    of this feature, see the new Alerts and notifications

    option on the Mercury Configuration menu..

  • Lingering Mailboxes  This

    is a new performance option for the MercuryI IMAP server,

    especially aimed at people using "stateless"

    IMAP clients such as webmail packages. When it is turned

    on, Mercury defers breaking down the memory image of

    the mailbox when an IMAP connection terminates; if a

    new connection for the mailbox arrives before the standdown

    period has elapsed, it can be reused at once, hugely

    reducing the startup time for IMAP connections. Enable

    this option in the "Files" page of the "Core

    module" configuration dialog.

  • IMAP INBOX now cached

     The Mercury IMAP server now caches the IMAP inbox,

    meaning that connecting to it will be significantly

    faster than in previous versions.

  • IMAP Server performace


     Server performance, particularly

    when opening large folders, has been dramatically improved.

  • DST-proof POP3 UIDs

     Because of a long-standing bug in Windows, the

    MercuryP POP3 server in the past reported different

    UIDs for messages after a change in Daylight Savings

    Time, resulting in clients re-downloading messages they

    had already seen. This problem has been fixed in v4.61,

    but the fix is disabled by default, because enabling

    it will cause one last re-download. You can turn it

    on whenever you're ready in the MercuryP configuration


  • MB_MLSS heavily improved

     MB_MLSS, the MercuryB module that allows web-based

    management of mailing list subscriber settings, has

    been heavily overhauled. It now has options allowing

    subscribers to retrieve their passwords if they have

    forgotten them, and to change settings for all lists

    to which they are subscribed. As well, users can now

    select lists from drop-down controls instead of typing

    in their names (if you have 50 or fewer lists), and

    the service manipulates mailing lists directly, rather

    than going through the Maiser mail server interface.

  • Mailing list password auto-assignment

     Mercury's mailing list manager can now be instructed

    to auto-assign passwords for new subscribers to mailing

    lists. This, combined with the new capabilities of the

    MB_MLSS module (see above) makes mailing list management

    easier and more secure.

  • SMTP server enforces size


     In previous versions of

    Mercury, the SMTP server could be told to refuse incoming

    messages larger than a particular size, but only if

    the connected client used the ESMTP SIZE declaration.

    In v4.61, MercuryS now refuses *any* message larger

    than the size you specify, whether or not there is a

    SIZE declaration. This change *might* confuse some older

    SMTP client programs (we expect this to be a very rare

    occurrence if at all), but has become increasingly important

    in the age of spam and mail-borne viruses.

  • POP3 Server completely


     The MercuryP POP3 server

    has been totally overhauled, and is now substantially

    faster than in previous versions.

  • POP3 login-time listing


     This powerful new feature

    allows users to control the messages the Mercury POP3

    server will show them by adding a simple command to

    their POP3 username... For example, if you only want

    to see urgent messages from the ""

    domain, you would login to your POP3 mailbox as username

    (urgent, The constraints that are

    available are described in more detail in the Mercury

    manual and online help. We anticipate this feature

    being especially useful for people who use cellphones

    or other low-grade connectivity devices to check their


  • MSendTo commandline mailer

     This new utility allows you to send mail from

    the commandline. It is quite sophisticated, and can

    generate a wide range of message types, including digests

    and unlimited numbers of MIME attachments. MSendTo can

    be used in scripts or called from programs to send mail

    via Mercury.

  • Threading in the core module

     In the past, the Mercury core module has been

    single-threaded (meaning that it can only ever be doing

    one thing at a time). With increasing processing of

    mail via external processes such as Mercury policies,

    SpamHalter, Content Control, filtering rules and so

    on, the time it takes to process a message in the queue

    has been getting longer and longer. As of v4.61, the

    Mercury core module now supports limited threading (it

    runs up to seven worker threads), which significantly

    improves queue throughput on heavily-loaded systems.

  • Many, many fixes,

    including problems with IMAP UIDs being lost or duplicated

    after crashes, problems with the loader queue quarantine

    message being delivered multiple times and others.

As well, a comprehensive new developer guide and sample

code for people interested in developing their own Mercury

Daemons is nearing completion and will be made available

in the next few weeks: an announcement will be made here

when it is released.

Sub Categories
Hide topic messages
Enable infinite scrolling
All posts under this topic will be deleted ?
Pending draft ... Click to resume editing
Discard draft