Describe a few things in some clearer detail.

lib/perlfaq9.pod

@@ -451,12 +451,24 @@ the MIME/QP encoding. Decoding BASE64 becomes as simple as:
     use MIME::Base64;
     $decoded = decode_base64($encoded);
 
-The Email::MIME module can decode base 64-encoded parts transparently so 
-the developer doesn't need to worry about it.
+The Email::MIME module can decode base 64-encoded email message parts
+transparently so the developer doesn't need to worry about it.
 
 =head2 How do I return the user's mail address?
 
-Ask them for it.
+Ask them for it. There are so many email providers available that it's
+rather unlikely the local system has any idea how to determine a user's
+email address. The one notable exception is for organization-specific
+email (e.g. foo@yourcompany.com) where policy can be codified in your
+program. In that case, you can look at $ENV{USER}, $ENV{LOGNAME}, and
+getpwuid($<) in scalar context, like so:
+
+  my $user_name = getpwuid($<)
+
+But note that you still cannot make any assumptions about whether this
+is correct unless your policy says it is. And then there are things like
+localpart extensions (foo+bar@example.com). You really are best off
+asking the user.
 
 =head2 How do I send mail?
 
@@ -506,7 +518,8 @@ Telling Email::Sender::Simple to use your transport is straightforward.
 Email::MIME directly supports multipart messages, and in fact the simple
 case of a plaintext email still has one 'attachment'. Email::MIME
 objects themselves are parts and can be attached to other Email::MIME
-objects. 
+objects. Consult the Email::MIME documentation for more information,
+including all of the supported methods and examples of their use.
 
 =head2 How do I read mail?
 
@@ -521,6 +534,10 @@ Use the Email::Folder module, like so:
     my $mime = Email::MIME->new($message->as_string);
   }
 
+There are different classes in the Email::Folder namespace for
+supporting various mailbox types. Note that these modules are generally
+rather limited and only support B<reading> rather than writing.
+
 =head2 How do I find out my hostname, domainname, or IP address?
 X<hostname, domainname, IP address, host, domain, hostfqdn, inet_ntoa,
 gethostbyname, Socket, Net::Domain, Sys::Hostname>