Microsoft Office Tutorials and References
In Depth Information
WHAT IS SMTP?
For those who need it, here is a quick SMTP primer as it relates to SharePoint. Simple Mail Transfer
Protocol is an industry standard and is used to send mail from server to server. SMTP uses port
25 to do its work, so that port has to be available for its use. This means you can’t enable SMTP
(and therefore SharePoint’s incoming email) if you’ve installed SharePoint on the same server as
Exchange (unlikely, but it could happen). That is because Exchange is already using that port and
When you enable SMTP for IIS, it will create a number of folders under the IIS’s folder LocalDrive: \
Inetpub in a folder called Mailroot This folder will contain a Drop folder, in which mail sent to .
the server will be stored. It is this folder that SharePoint checks for email sent to the local lists or
libraries. If email is found addressed to one of the lists or libraries, SharePoint will read the email
header and contents; parse the information for title, content, and attachment information; and
deposit the mail as an item for that list or library.
Interestingly, despite that SMTP is generally used to focus on sending mail rather than receiv ing it,
using SMTP for receiving mail for its SharePoint services is rather clever.
Think about it; SharePoint Foundation is free (and the very first version of SharePoint, the impetus
for all this, was free as well). So, it needs to use what is already available on the server at no extra
cost to do what it needs to do, as well as using only Microsoft products to get jobs done. So, it uses
IIS and SQL. IIS is particularly the focus of SharePoint because the front-end servers must handle
web pages and use ASP.NET. So, if someone wanted the capability of sending items to lists and
libraries in SharePoint rather than logging in, how would they do it, for free, with nothing more
than what is already available?
SMTP, of course. It has its shortcomings, but it allows the pickup and drop-off email messages on
the IIS server. SharePoint only uses the drop-off capability, the ability to get the messages meant for
its server address, but that still works. This also explains why the default for the server address for
incoming email is the SharePoint server’s name in DNS. It’s already set, so just use what works.
SMTP also has Pickup, Queue, and Badmail folders. These are relevant if you are using SMTP to send
mail from the IIS Web Sites to other servers (and other addresses outside the domain). However, the
folders aren’t really used for receiving email. (Although Badmail can be, if a message isn’t address
cor rec tly.)
Only one SharePoint server in the farm needs to have SMTP enabled, because SharePoint really
supports only one SMTP drop location per farm. However, this installation may be the only server
on the farm, and it will certainly be the first one, so it is a good idea to at least learn how to enable
SMTP and set up incoming email and to have the first server be the one that supports incoming
email at least until other servers are online.
Back in the day, to enable SMTP, you’d go to Add/Remove Programs, click Add/Remove
Windows Components, and scroll down to SMTP. Now, with Server 2008 and 2008 R2, SMTP is