Would you use SPWebApplication to get information like the SMTP address of the SharePoint site?

Yes, since this is a Web Application level setting. You would iterate through each SPWebApplication in the SPWebApplication collection, and then use the appropriate property calls (OutboundMailServiceInstance) in order to return settings regarding the mail service such as the SMTP address.
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Yes, since this is a Web Application level setting. You would iterate through each SPWebApplication in the SPWebApplication collection, and then use the appropriate property calls (OutboundMailServiceInstance) in order to return settings regarding the mail service such as the SMTP address. Side Question: I got asked if there are other ways to send emails from SharePoint. The answer is yes, there is. You can use the SendMail method from the SPutility class to send simple emails, however it is not as robust as using the System.Net.Mail functionality since it doesn't allow things like setting priorities on the email. (More...)

No you cannot. However, you can exchange contact information lists with Microsoft Outlook.
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A site definition is a methods in SharePoint for providing pre packaged site and list content. (More...)

Web Part Page Gallery in SharePoint is the default gallery provided by Microsoft that comes installed with SharePoint. Site Gallery is specific to one sharepoint website site. Virtual Server gallery is specific to that virtual server and online gallery is available for download web parts from MSDN. (More...)

SharePoint-based Web sites can be password-protected to restrict access to registered users, who are invited to join via e-mail. In addition, the site administrator can restrict certain members' roles by assigning different permission levels to view post and edit. (More...)

If you want your site to have anonymous access enabled (i.e., you want to treat it like any site on the Internet that does not ask you to provide a user name and password to see the content of the site),
If you want to make your sharepoint website available on Internet and anybody can use it than you can follow below steps:

1) Log-in as an administrator
2) Click on site settings
3) Click on Go to Site Administration
4) Click on Manage anonymous access
5) Choose one of the three conditions on what Anonymous users can access:** Entire Web site** Lists and libraries** Nothing Default condition is nothing; your site has restricted access.
The default conditions allow you to create a secure site for your Web site. (More...)

Yes. You can manage this process using the Administration Site Settings. Simply add users via their e-mail alias and assign permissions such as Reader or Contributor. (More...)

The only files restricted in Sharepoint are those ending with the following extensions: .asa, .asp, .ida, .idc, .idq.Microsoft reserves the right to add additional file types to this listing at any time. Also, no content that violates the terms of service may be uploaded or posted to the site. (More...)

SiteMapPath (More...)