Hmm, common initial issue. Without any more details, I will attempt to assist. Since your Outlook seems to be working fine, I do not believe or foresee this as any issue with any firewall or router config, but it may be on the server-side...again though without any tech details on the server you have OG on, I cannot list things for you to check.
So, let's check the easiest thing: Check the smtp authorization (if required) in the advanced settings of Outlook or other e-mail program you are using. HINT: Look at the e-mail account settings in Outlook (especially the advanced settings for "outgoing mail" by opening up the account properties for the e-mail account, then click on "More Settings" button at the bottom right hand corner. Then click on the "Outgoing Settings" tab at the top of the new window that appears.... copy down any information you see down to use in OpenGoo (hereinafter referred to as "OG") e-mail setup. Often, this is set to "use same settings as incoming server" which is important to note. Remember, you need to configure OpenGoo smtp for the web application itself (i.e. in the Administration area>Mail Settings) and also for each individual e-mail acccount for the users.
If your server is on an ISP like AT&T or Bellsouth, remember that the server's outgoing e-mail account MUST be one that they have issued or allowed. For instance, Say I set up OG on a server of mine that is on a Bellsouth ADSL line. I must configure the smtp for the server to utilize accountholdername@bellsouth.net as the "outgoing" e-mail account and set smtp to use this address for all outgoing mail. Bellsouth's mail server would bounce back anything else.
As a result of their efforts on cutting down SPAM, most ISPs do not allow relay of email or their users sending outgoing email to various other smtp servers. Therefore, you will need to get your ISPs smtp server address as well as have them set you up with a user name and password (if applicable). Then setup your email with the regular incoming server info (i.e. for POP) and then use your ISPs outgoing (SMTP) server info which should fix your problem. Again, check to make sure that the SMTP is configured to use the ISPs allowed account (username/password) if necessary.
(I will add more on the specifics of configuring OG in about an hour or so)
I did not look at your PM first, though so, I was not sure of the server platform you were using. Since your using IIS, I would check the following in the PHP.ini file that OpenGoo is using:
[mail function]
; For Win32 only.
SMTP = localhost
smtp_port = 25
; For Win32 only.
;sendmail_from = me@example.com
NOW, change "localhost" up there to your smtp mail server address (i.e. something like mail.yourserver.net). If you do NOT have an SMTP server setup on that server, use your ISPs smtp server address. Next, uncomment the "sendmail_from" item, then change me@example.com to whatever ISP e-mail account you use (or if it is a local smtp server, then use account info for that smtp server).
Now, you still need to configure OpenGoo in the administration area > mail settings to reflect the same information; as well as, for the users e-mail account setups.
Check all of that and you should be good. If not, check any firewall on the IIS server and ensure that port 25 is open for smtp traffic OUTBOUND and INBOUND. Warning here though, if the IIS server is on a public-accessible IP address (i.e. available to the outside internet), then you need to ensure that you have setup smtp authorization with your local smtp server and to disallow relaying...otherwise your server will eventually get swamped by SPAMmers searching for relaying smtp servers...yes, this happens very quickly. If your the paranoid-type systems admin, like me, you can visually see this on your traffic logs real-time from the moment you make a anon-relaying smtp server available on a public IP address. Amazing to watch. So watch out for that.
Hit me back in this topic or on PM if your still having issues after checking all of that.
If you need your own easy to install and configure smtp server on the Win32/Win64 platform... try
http://www.softstack.com/freesmtp.html
