How are you using the Windows 2003 POP3 Server?

I saw a link on the “hellomate“ MS Exchange blog to a post singing the praises of the POP3 Server that comes in Windows Server 2003 and it reminded me that I wanted to write about this and ask people to comment or write, and tell me what you are using the POP3 server for, and how you like it. 

For Exchange admins, the POP3 server can be confusing, because the “Manage Your Server” wizard that comes up when you install Windows 2003 offers to let you select the “E-mail server” role for the server, and when you do that, it installs the POP3 service and the SMTP service.  Unfortunately, the POP3 service is incompatible with Exchange, so Exchange 2003 setup will tell you to remove the POP service before it allows you to install Exchange. 

If you are using the POP3 server, what do you wish it did, and how would it change how you use it?  My team is responsible for the future of this service (among other things), so you’re getting an opportunity to talk directly to the right person!

Comments (52)

  1. Adam Hill says:

    My biggest issue is looking at the log of failed connects or errors at the end of the transfer as reported in the Server reports.

    How do you look at them and see if there is something you need to fix. Simple rules would be cool too (if To: = some email address go here)

  2. Simon says:

    We would find IMAP support more useful than POP3 – as this provides the ability to have the clients connect from multiple workstations and roam more.

  3. Michael B. Smith says:

    We spend significant funds on a 3rd party mail server, that provides pop3/smtp services. I’d love to not have to spend that anymore. The primary feature missing from the W2k3 pop3 server is webmail. It would be really nice if webmail functionality was available.

    Secondly, and a much lower priority for us, would be IMAP support (very few of our users want IMAP capability).

  4. Rodger Ballard says:

    I use the Windows 2003 SMTP/POP3 servers. I find them to be very stable. The only addition I would like to see would be the ability to authenticate users against the SMTP server using their POP3 login when you are using the Encrypted Password File. It seems only natural to login to the SMTP server the very same way using the same account you use for your POP3 mail.

    What would the possibility of this be?

  5. David Lemson says:

    I’m also interested in hearing about the context in which people are using the Windows 2003 POP server. Do you run an ISP with it? Are you using it for your personal mail? Feel free to send me personal mail with the answer if you like, too.

  6. Rick says:

    The features I would most like to see are:

    1. Distribution list

    2. Alias support

    3. webmail

  7. Johan Sandqvist says:

    I’ll second Rick’s opinion. Add IMAP and (of course) SSL/TLS support for all protocols and I would replace my sendmail server at home immediately. I would use it for personal/small business use. At work of course Exchange is the best solution.

  8. s b says:

    using it as it should. although you should add a function that would allow the server to send email directly and try it indirectly.

    my ISP blocks doing it directly in on a few cases.

  9. Dave says:

    I like the pop3/smtp combination in windows server 2003…but it seems really odd to me that I cannot create a ‘forwarding address’ (whereby email sent to is redirected to

    Either I’m mistaken, or the software doesn’t support the feature…? Email forwarding is a very common task (isn’t it?)

  10. Richard Penn says:

    I second Dave’s comment on forwarding – I think a Win2k3 server out of the box should be able to what a simple Unix share on a hosting service can do, and forwarding is always a part of that. I switched to a dedicated server and got a reduction in service by going to windows.

  11. Noggin says:

    I think that its very stable, but is missing a few features. I also want mail forwarding and the ability to set up a "catch-all" mailbox on each domain (unless this can be done already, i haven’t been able 2 do it yet?)

  12. Jason says:

    I need a forwarding function.

  13. Sethalon says:

    Let me add to the laundry list:



    Mailing lists

    For webmail, I’m kinda torn. That’s getting into Exchange/OWA. I think most of us are looking for something light here. Exchange is heavy duty.

    Better management

    The ability to add plugins (virus/spam scanners)

  14. JohnP The MCSE says:

    I use the Win2K3 pop/smtp for the family at home (4 different virt. domains) and it seems to work great for the 50 users (family members) or so that use it. The bells and whistles that I enjoy at work would be nice.

    I agree with all of the above. I work for an ISP that is a heterogenous scheme and the management will not even consider this as an option due to the limitations/Lack of features. Webmail is a must for about 80% of our 2000 or so users.

  15. Simon says:

    Webmail – i am working on that at the monent – it is actually quite easy to program.

    Services like forwarding / email lists / aliases are easier to acomplish using an external provider like

    (I know it depends on you volumes scalability etc, but for the home / small business IMHO).

    The thing I am strugling with right now is finding a cheap but decent virus scanner which will sit between the SMTP server and the POP server somehow.

  16. Josiane says:

    I need a virus scanner, Web Mail and a security authentication using a CA (certificate authority).

  17. alex says:

    What about anti virus support?

  18. Dan Slarve says:

    While in process of rolling it out now, it will solve a tremendous amout of issues that I currently face w/ trying to retrofit and support Siebel ERP implementations that use both pop and smtp (dependent upon the functionality required). By handing this functionaly off to a windows-based platform using win 2003, I can eaisly manage this with less effort.

  19. -=[ ArcAiN6 ]=- says:

    I’m currently running the pop3 e-mail server on windows 2003 for personal use for myself and friends as well as a backend mail server for the network, i don’t know if there is anything out there as of yet, but i would like to see, or know of any products on the market that can add, remove, and edit user accounts on the server, preferrably in PHP, or perl. the server runs great for what i use it for, although i have noticed at times of peak network traffic that the e-mail server seems to get lost in the confusion and claims failures at the end of the send/recieve process, but as of yet, i haven’t noticed anything drastic about that, as the users appear to be getting thier mail fine, only the server sees a problem.. kinda off, but hey, what do you expect from a bundled option anymore?

  20. talya says:

    Hi i am using Exchange 2003 as a email server, and on the client pcs I wanted to know how to display the users in the address contact list of Ms Outlook without having to install Exchange Server as the mail service. I installed the POP3 service in Outlook. It works to send a e-mail to a user, but you would have to know the email address, my problem is, this is an establishment with 800 pcs, and it has been configured with pop3 only and the address list does not display the list as an offline global address does which i found out about after the fact, and i wanted to avoid having to go back around and edit each pc, I wanted to know if I could just make a change from the server end

  21. Jason says:

    Can’t use Eudora unless SSL/TLS/IMAP

  22. Ken says:

    Not really using it at all as it is apparently broken. Our company recently purchased a 2k3 server and I’ve spend a week trying to get the smtp service to put incoming messages into their associated mailboxes.. Am I wrong in assuming that is the task of the service? Incoming mail gets as far as the Drop folder and never makes it to the user’s box. Do I *need* exchange server to get this to work? The MS knowledgebase says smtp’s only job is to stick incoming mail in the drop box. Any help/suggestions would be appreciated ๐Ÿ™‚

  23. Ken says:

    Also, to ArcAiN6 above, if you’re using AD to authenticate your mail users, you can in fact currently use php to add/remove/change users in the AD. The php ldap functions would be of some use, although I’ve been having problems ldap_bind()ing to our win2k3 AD.

  24. David Lemson says:

    Talya: I’m afraid we’re talking about very different things. But I have to ask why you aren’t using the client to talk to the Exchange Server in its native mode. But in any event, it is possible to configure Outlook or Outlook Express to use LDAP for name resolution. In this case, you’d point it to a global catalog server. It’s not as nice of an interface as you get with the address list with Exchange.

    Jason: Eudora does support POP, not just IMAP. In fact I bet most Eudora users use POP, since that’s all most ISPs support (or at least advertise).

    Ken: it sounds like you have not installed the POP service? Or perhaps you haven’t configured it? You can find its configuration in the Internet Services Manager. You are right that the SMTP service only puts mail in the drop directory, but when you install the POP service, it installs a hook into SMTP that makes it deliver mail to the mailboxes that the POP service knows how to check.

  25. Ken says:

    I have installed and configured the pop service, it doesn’t seem to do what it’s supposed to, although I can connect to it from a client. Also, if I stick a message in a mailbox I can get it just fine. Perhaps I have to reinstall the pop service or something.. I had issues with delivery out of the domain before and ended up reinstalling IIS to fix it. I’ll give it a shot and report.


  26. opsi says:

    As Webmail i use NOCC (IIS + php) it works nice

  27. Dave M. says:

    I need forwarding. I would love the simple ability to create a catchall account.

    I would also love to be able to do a handful of things programatically (using ASP.NET). It would be very helpful to give my website users the ability to create accounts, forwarding accounts and catchall accounts for their domain in a hosted environment.

  28. Matt says:

    i would use it, but for a webhosting company it just doesnt have enough! It would be brilliant if it could do all that other email servers can! and lets face it at £3,000 for enterprise it should be much better!

  29. ryan says:

    I am using this as a personal mail server (it sits after a spam/virus filter).

    Features it could do with is web mail (outlook express lookalike) catchall account, and forwarding.

    As far as the web mail/exchange argument goes, in my opinion, most people who will deploy this will be small business/individuals, who may not want the extra expense/groupware side of exchange. The ability to have a reasonable email system for internal clients and external access bundled would be a great selling point for Server 2003.

    An outlook express style webmail clent would also be a good selling point for an ISP as this is what most people are used too.

  30. Roger Guess says:

    I am using POP3 with SMTP on my Win2k3 standard because I honestly cannot afford anything else yet. However, it has worked perfectly so far. Some install problems, but removing/adding the mail server role fixed it.

    For us, no domain, just a single stand alone server. So we are just using the encrypted password file. A mail box administration tool would be great. But if you do all these new features, doesn’t that just mean a small percentage just won’t need exchange?



  31. Ron Bruurs says:

    The ability to reset password would be nice

  32. Pretselz says:

    Can’t someone just come up with a script to do the following:

    1. Look at stuck files in the DROP directory (dropped by SMTP for alias domains)

    2. Parse the second string (x-mail line) and take the string BEFORE the "@" sign (the username)

    3. Take the email that was parsed (step 2), and drop the said email on the user’s folder under the default DOMAIN

    This would (partially) enable forwarding of emails from an alias domain to the LOCAL/DEFAULT domain.

    So, if I have DOMAIN.COM as my local/default, and have an alias of ALIASDOMAIN.COM, then an email to would be picked up by the user.

    Now, why can’t I do this myself? err, sorry but I don’t know enuf VB scripting to do this. ๐Ÿ™

  33. Gwyn Carwardine says:

    Boy do the Win 2k3 services suck.

    I’m having all sorts of problems;

    * I can’t delete an SMTP domain. There is no option anywhere. The best I can do is rename it

    * Now SMTP seems to have forgotten it has any domains! Whenever I send a message to one of the mailboxes within the domains I get an NDR

    * How do you tell SMTP what directories to use (can’t find this anywhere now)

    * Was trying to download a very large file (8.5Mb) over a dialup from the POP3 service and the server kept terminating the connection. I did have Proxy Server in the way so perhaps that was doing something?

    * Distinct lack of documentation with 2k3 about the SMTP service.

    It’s very very very annoying and that’s without having even got onto something as blindingly obvious to anyone except a complete fuckwit who’s never used mail before as a catchall entry. Can Microsoft not actually excel at anything? Do they have to continually produce second rate products that do, at best, just about enough of the job, but badly.

    BTW. Please exclude .NET from this as it is actually very fine indeed!

  34. Tommy says:

    I have had so many problems getting mail to send with my SMTP server. I set it up fine and it sends fine but if I want a user to authenticate before sending it authenticates the first couple of times and then starts asking for the password. I like the pop3 service for receiving but I’m just having hell configuring the SMTP to work properly.



  35. J.P. says:

    I love the fact that the server is easy to use, but it really needs to have more features. I second the aliases and forwarding control.

    Oh, by the way, I hate MMC plugins.

  36. Frankie says:

    using it as normal but really wish it had a RBL or blackhole lit feature.

  37. Chris says:

    Hi All,

    Mail enable has a free version of thier pop3/smtp server. it doesn’t have webmail but you can find tons of them @

    Imail express is also free. I’m not sure if that has webmail or not and it only supports 10 users I think but my choice has been to just use mail enable standard and check my email using outlook.


  38. Matthew Michalek says:


    I have 2 domains and am trying to add a mail box to each with the same name ie, and I can add it to one domain but the second then says user already exists. Does this mean you cannot have multilpe emails under 1 user? Is it possible to solve this problem.

    Thanks in advance


  39. Kimball Johnson says:

    Mr. Lemon,

    I am very grateful that Microsoft was kind enough to include a POP3 server. The SMTP service has very limited utility without it.

    Another valuable addition would be a true LDAP service. I became very attached to the LDAP server in Site Server 3.0 and have missed its straightforward interface in Active Directory.

    However, the setup and configuration for the POP3 server is not at all intuitive and there is no decent documentation. The existing CHM file and the on-line KB articles are only useful to people who ‘already understand how MS decided to do it’ and only need a refresher on syntax.

    Frankly, I have been unable to get the very basic arrangement working between the following services: SMTP, POP3, DNS and OL Express or OL2002.

    There is no decent explanation of what MS-SMTP considers a ‘default’ account, much less what a ‘normal’, ‘local’, ‘remote’ or ‘alias’ account is. While win2003 allows the default account to be renamed (it defaults to the server name within the ad domain name within the the external dns name, if you’re configuring ad to be a sub-domain of a commercial domain).

    Then, the POP3 server creates ‘domains’ but its actually creating SMTP service domains and is unwilling to create mailboxes for a domain that the SMTP service created. It will not even acknowledge the existence of a domain created by SMTP rather than POP3. This is enormously puzzling to the uninitiated and there is no documentation that even mentions it.

    And the relationships between the domains created by default by SMTP, those created by POP3, those created in AD, and the pointers in DNS is not at all obvious.

    In some of the other blog entries I noted that others are experiencing the failure of these services to integrate and interoperate as expected, not forwarding mail to mailboxes,etc.

    It’s clear that MS believes that SMTP and POP3 are similarly for the (unix) tech-head and gives them only lip service in its docs, the same way it does for its telnet implementation. I am very wearied by the need to weed through extensive KB articles referring to Exchange, Outlook, SMTP and so forth to find the few crumbs of (very disappointing) information regarding POP3.

    Now this would be ‘normal’ considering there is no specific revenue stream associated with these services in contrast with programs like Exchange.

    But if you want to really help me out, I would like some serious explanations of what, how, why, when and whether the four elements of this facility (SMTP,POP3,DNS,OL) work together. Having pictures of where the document flow goes in a generic SMTP/POP3 world has nothing to do with how to get these very Microsoft-ese services properly integrated.

    I perceive this service as an excellent management feature since its possible to create LAN-only based email domains that are useful for services and maintenance reporting between servers, admins and scripted tools.

    The other applications like a home mail server, replacement for small commercial mail servers, etc. seem to me to be limited by various scalability and bandwidth issues. Although they are intriquingly inexpensive.

    So, what can you actually do for me in the short run?


    Kimball Johnson

  40. Seb Lau says:

    I haven’t had any major problems, the webmail I programmed from scratch in PHP, I’m just working on automating adding accounts and changing passwords.. I’m not using Active Directory so my only option is to use ‘winpop’, which is very limited…

  41. Seb Lau says:

    ermm. what method of encrypting the password does the pop3 server use for Encrypted Password File? A standard MD5 encryption for ‘test’ gives: ‘ Åk-F!Ës-ÌNâ&’ยฆ÷’

    however the pop3 lock file gives: ‘èโ€นโ‚ฌöล’โ€ฐ<×’? Knowing this work make changing passwords far easier via the MD5 module of Perl..

  42. Shahin Fadaei says:

    it’s good that microsoft included pop3 along with SMTP in windows ….. but I have a problem …. once I add a user for a domain in pop3 server then I cannnot have the same user for a different domain ….. has anybody had this problem before ???


    Shahin Fadaei

  43. skippy says:

    For the forwarding aspect it is very simple to have a script run on a box that checks the drop directory. I have created a script that reads the email, changes the headers based on the incoming address and then forwards to the external domain. Works great.

  44. Xristos Nikolopoulos says:

    i would like to know how i can create a php or asp form that will allow visitors of my page to sign-up automatically for a pop3 account…

    also, i want authorization for smtp like pop3 as an option…

    imap comes last for me cause i don’t really need it…

    (i think there should be included the functionality of auto sign up for new user in a web interface….)

    plz reply how i can do these at:

  45. For some of the suestions above says:

    The Catchall mail box and autoforwarding and aliasing.

    Register an event sink for the ISMTPOnArrival_OnArrival event. You can filter register components like spamassasin and a virus scan dll. You can also make a query to a sql server or access db to check for aliases and catchall mailboxes. Then you could create a simple asp admin page to administrate the SQL or access database for each of these options.

    The SMTP and the POP3 service are both robust services that come with limited administrative interfaces….

    Hey it is the same services exchange server uses…….

    Jon Lindley

  46. Antti Keskinen says:

    What I would like to see most is the ability to fetch POP3 mail from an external server easily. This allows better implementations of virus scanning, spam blocking or similar if a client doesn’t have one.

    An example as follows: we have a client that uses e-mail accounts from their ISP. The ISP has not, however, implemented any type of spam or virus checking routines, and as such, the amount of spam/infected mail to the client is drastic, causing a multitude of problems. Using a virus scanner for every workstation is an option, but consider installing 1000s of scanners ?

    They are planning on moving to the Windows 2003 Server environment (for other reasons than mail, too), so having the opportunity for the 2003 server to fetch their mails from the ISP with POP3, scan them for spam/viruses and then put them available in local mail boxes (on the 2003 server) would be a huge advantage, as standard mail-redirection service from the ISP requires a rather large monthly investment.

    If you’ve already solved this, then notify me

    antti.keskinen (at)

  47. David Lemson says:

    Antti: I believe that some of the "POP3 Connector" products listed at actually submit to the local server via SMTP, and so therefore they should be able to submit to the Windows SMTP/POP server combination.

    Update to this post: I have actually changed jobs and I’m afraid that I no longer am working on the future Windows POP server. But the people who are do know about this post and do read it to get ideas for the future. It’s just that I need to set expectations that I am not going to be able to answer questions about what we will have in the future in the Windows POP server.

  48. Kevin Buchanan says:

    Well…I am not using it! I have tried, but can’t get it work. I can send SMTP to external (like hotmail accounts), but I can’t receive mail. I keep getting NDR saying the recipient is invalid; but I have "know" the recipient is valid (b/c it exist in the POP3 domain).

    Any links on how to do this? (spoon feed me…I am fed up).

    Otherwise, I think anti-virus on the server for messages is a must. Need I say something akin to Exchange LT? I upgraded from Exch 5.5 to 2k3 at work – piece of cake and easy to manage. I would like to use POP3/SMTP at home and in some client’s offices – but refer to above…I can’t get it work at home!! HELP!


  49. Starseed says:

    Forwarding and Aliasing…

    A funky but functional way to configure forwarding and aliasing for Windows Server 2003’s POP3 Service.

    I’m running with AD, so I have not tested this on a stand-alone server. This method is only recommended for home users or very small businesses without a permanent email infrastructure. To manage something like this in large domain environment would be nearly impossible. But for a few home users it works as well. I’m assuming a relatively experienced users is performing this task.

    Open ADUC and create an OU to host your alias users.

    You will need to create a child OU for each user and a user object for each alias.

    Create a child OU beneath your aliases OU for this username

    Add a user object for each alias and set the username to be the alias for that account.

    For example, if your user account was juser but you wanted an alias called "John.User" you would set the user name properties to "John.User". For advanced users, that is the sAMAccountName and userPrincipleName properties.

    I find it useful to set the "Full Name" box to the alias name so that it can be easily identified in ADUC. It’s easiest to set the passwords the same for all of the aliases for one particular user.

    Now, for the actual work. Configure a folder on your server and lock it down for the SYSTEM account and a service account with elevated priveleges of your choosing. For example C:WindowsPullMail with Administrator = Full Control

    You’ll need to make sure this folder is secured because it will contain passwords.

    Go to this site ( and download a well-known command line utility called pullmail. If this link is dead, search "pullmail" on google.

    Save pullmail to C:WindowsPullMail.

    Read the readme.txt file for complete pullmail syntax

    Now create a batch file for each user.

    In the batch file, create a line for each alias assigned to a user.

    The syntax would look something like this….

    C:utilitiespullmail myPassWord / /

    C:utilitiespullmail myPassWord / /

    C:utilitiespullmail myPassWord / /

    So we save this file as :WindowsPullMailusername.bat

    Now create a scheduled task for each username and execute the batch file for their username every few minutes or so.

    Make sure to run your tasks as your service account.

    This successfully gathers all the email from each alias user and dumps it to one mailbox.

    You could do the same thing with forwarding using pullmail.

  50. Starseed says:

    Other ideas…

    A script could be written to traverse the aliases OU and reset the password for all accounts under the username child OU and then update the password information in the batch file for their aliases.

    Group policy could be implemented to disallow the users in the aliases OU from logging on to a machine.

    On second thought for the task scheduling, it seems easiest to configure just one task and manage adding jobs by adding lines to the main batch. In other words, the main batch process would call the user-specific batch files.

    Example: (ProcessAliases.bat)

    call user1.bat

    call user2.bat

    call administrator.bat

    Example: (user1.bat)

    C:windowspullmail password / /

    C:windowspullmail password / /

  51. Dave Watkins says:

    I did start using the POP3 Service, but then I saw it didn’t do aliasing/forwarding and group/distribution lists, anti-virus and spam filtering (as mentioned by quite a few people) – so I have been writing my own version using C# and SQL Server. I must admit, its very memory hungry at the moment – but I am getting there ๐Ÿ™‚

  52. David Lemson says:

    Dave: It’s true, the POP protocol is very straightforward. Just make sure to consider the case where the same user has two connections at the same time!