errors in Sending email in iPhone - iphone

Question

I'm trying to create application that sends email
I used classes like
SKPSMTPMessage , NSStream+SKPSMTPExtensions, NSData+Base64Additions, HSK_CFUtilities, Base64Transcoder
but it gives me the following errors
Undefined symbols for architecture i386:
"_OBJC_CLASS_$_SKPSMTPMessage", referenced from:
objc-class-ref in MFViewController.o
"_kSKPSMTPPartContentTransferEncodingKey", referenced from:
-[MFViewController sendMail:] in MFViewController.o
"_kSKPSMTPPartContentTypeKey", referenced from:
-[MFViewController sendMail:] in MFViewController.o
"_kSKPSMTPPartMessageKey", referenced from:
-[MFViewController sendMail:] in MFViewController.o
"_CFHostCreateWithName", referenced from:
+[NSStream(SKPSMTPExtensions) getStreamsToHostNamed:port:inputStream:outputStream:] in NSStream+SKPSMTPExtensions.o
+[NSStream(SKPSMTPExtensions) getStreamsToHostNamed:port:inputStream:outputStream:] in SKPSMTPMessage.o
"_CFStreamCreatePairWithSocketToCFHost", referenced from:
+[NSStream(SKPSMTPExtensions) getStreamsToHostNamed:port:inputStream:outputStream:] in NSStream+SKPSMTPExtensions.o
+[NSStream(SKPSMTPExtensions) getStreamsToHostNamed:port:inputStream:outputStream:] in SKPSMTPMessage.o
ld: symbol(s) not found for architecture i386
clang: error: linker command failed with exit code 1 (use -v to see invocation)
keep in mind that I'm using Xcode 4.3 ,
what shall I do to solve this??
After adding the CFNetwork framework and SystemConfiguration framework ,
the number of errors decreased from 6 to 4 and it is now
Undefined symbols for architecture i386:
"_OBJC_CLASS_$_SKPSMTPMessage", referenced from:
objc-class-ref in MFViewController.o
"_kSKPSMTPPartContentTransferEncodingKey", referenced from:
-[MFViewController sendMail:] in MFViewController.o
"_kSKPSMTPPartContentTypeKey", referenced from:
-[MFViewController sendMail:] in MFViewController.o
"_kSKPSMTPPartMessageKey", referenced from:
-[MFViewController sendMail:] in MFViewController.o
ld: symbol(s) not found for architecture i386
clang: error: linker command failed with exit code 1 (use -v to see invocation)

Answer 1

This error message means that those classes search some objects in a framework that you haven't linked to your project. Here you can found what framework do you need: the CFNetwork framework.
I hope it helps!
EDIT
The other 4 errors might be caused by the incorrect importation of the SKPSMT classes. If that classes are downloaded as a library, you'll also need to link your app with that library.

Answer 2

Try adding the following linker flags:
OTHER_LDFLAGS = -lz -lxml2 -ltidy -ObjC