Can not play .m4a file in safari that is recorded in iOS application - avaudiorecorder

Question

I am having application in which i need to record audio and than upload it on the server and mail the link of the file to the user.
Now when I try to open the mail in mac or windows it works fine and i can hear the audio. But when i try to open the link in iPhone or iPad it won't play in it.
While i had a demo application made for the project and when i try the same thing, it worked.
Please help me out.
Thank you in advance.
NSArray *dirPaths;
NSString *docsDir;
dirPaths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
docsDir = [dirPaths objectAtIndex:0];
if ([txt_RecordingName.text isEqualToString:#"Untitled"])
{
strFileName = [NSString stringWithFormat:#"Recording %d.m4a",[appDelegate.db getMaxId]];
soundFilePath = [docsDir stringByAppendingPathComponent:strFileName];
}
else
{
strFileName = [NSString stringWithFormat:#"%#.m4a",txt_RecordingName.text];
soundFilePath = [docsDir stringByAppendingPathComponent:strFileName];
}
NSDictionary *recordSettings = [NSDictionary dictionaryWithObjectsAndKeys:
[NSNumber numberWithInt: kAudioFormatMPEG4AAC], AVFormatIDKey,
[NSNumber numberWithFloat:16000.0], AVSampleRateKey,
[NSNumber numberWithInt: 1], AVNumberOfChannelsKey,
nil];
newURL = [NSURL fileURLWithPath:soundFilePath];
audioRecorder = [[AVAudioRecorder alloc]
initWithURL:newURL
settings:recordSettings
error:nil];
audioRecorder.delegate = self;
[audioRecorder prepareToRecord];
if (!audioRecorder.recording)
{
AVAudioSession *session = [AVAudioSession sharedInstance];
[session setCategory:AVAudioSessionCategoryRecord error:nil];
[session setActive:YES error:nil];
[audioRecorder record];
counter = 0;
[btnPauseRecord setEnabled:TRUE];
}
recordingTime = -1;
[self showRecordingTime];
[lbl_Recording setHidden:NO];
[lbl_PressToStop setText:#"Press to pause"];
[lbl_PressToStop setHidden:NO];
[lbl_ListenToRecording setHidden:YES];
[lbl_RecordingAgain setHidden:YES];
[btn_ListenToRecording setHidden:YES];
[btn_RecordAgain setHidden:YES];
txt_RecordingName.text = strFileName;
}
else
{
[audioRecorder stop];
audioRecorder = nil;
AVAudioSession *session = [AVAudioSession sharedInstance];
[session setActive:NO error:nil];
isRecording = FALSE;
[btnPauseRecord setEnabled:FALSE];
[txt_RecordingName setEnabled:TRUE];
isPaused = TRUE;
[lbl_Recording setHidden:YES];
[lbl_Save setHidden:NO];
[btn_Save setHidden:NO];
[lbl_ListenToRecording setHidden:NO];
lbl_ListenToRecording.text = #"Listen to Recording";
[lbl_RecordingAgain setHidden:NO];
[btn_ListenToRecording setHidden:NO];
[btn_RecordAgain setHidden:NO];
lbl_PressToStop.text = #"Press to resume";
[lblPauseRecord setHidden:YES];
[btnPauseRecord setHidden:YES];
}