URL Scheme Attachment Microsoft Outlook app

Question

I'm trying to make an app that generates a file and fills all email fields so the user just has to enter the body. I also give the user the possibility to choose between the native iOS email app and the Microsoft Outlook app (if it has it installed).
When I implement this to prepare the email to be sent in native email app I have used MessageUI framework wich make easy attaching the file, but for Outlook app I have to use an URL Scheme (ms-outlook://) and it seems that there are no easy way (or a way at all) to attach files.
Does anyone have successfully sent an attachment from another app throught Outlook app?

Answer 1

I am posting this answer based on "Something is better than nothing". I know it is not possible to send an email with a pre-attached file using iOS App so I have managed to find a way to, at least, be able to send an image file in the email.

// Create an array of recipients for the email.
NSArray* emailRecipients = @[@"example@email.com", @"example2@email.com"];

// Create a mutable string to hold all of the recipient email addresses and add the first one.
NSMutableString* emailTo = [[NSMutableString alloc] initWithString:emailRecipients[0]];

// Loop through all of the email recipients except for the first one.
for (int index = 1; index < emailRecipients.count; index++)
{
    // Add a semicolon and then the email address at the current index.
    [emailTo appendFormat:@";%@", emailRecipients[index]];
}

// Get the email subject from the subject text field.
NSString *emailSubject = @"Your Email Subject";

// Encode the string for URL.
NSString *encodedSubject = [emailSubject stringByAddingPercentEncodingWithAllowedCharacters:[NSCharacterSet URLHostAllowedCharacterSet]];

// Define your image's size
NSString *htmlBody = (@"<div style=\"width:450px;height:797px;\"><img src=\"http://your_website.com/your_image.jpg\" style=\"width:100%;height:100%;\"></div>");

// Encode the string for URL.
NSString* encodedBody = [htmlBody stringByAddingPercentEncodingWithAllowedCharacters:[NSCharacterSet URLHostAllowedCharacterSet]];

// See if the subject or body are empty.
if (![emailSubject length] || ![emailBody length])
{
    // Exit.
    return;
}

// Create a string with the URL scheme and email properties.
NSString *stringURL = [NSString stringWithFormat:@"ms-outlook://compose?to=%@&subject=%@&body=%@", emailTo, encodedSubject, encodedBody];
// Convert the string to a URL.
NSURL *url = [NSURL URLWithString:stringURL];
// Open the app that responds to the URL scheme (should be Outlook).
[[UIApplication sharedApplication] openURL:url];

This sends the image file embedded in the email body easily. You may have to adjust the size according to your image.