text: //
  //  MCOSMTPCheckAccountOperation.h
  //  mailcore2
  //
  //  Created by DINH Viêt Hoà on 3/29/13.
  //  Copyright (c) 2013 MailCore. All rights reserved.
  //
  
  #ifndef MAILCORE_MCOSMTPOPERATION_H
  
  #define MAILCORE_MCOSMTPOPERATION_H
  
  #import "MCOOperation.h"
  
  /** This is an asynchronous SMTP operation, used for sending messages. */
  
  NS_ASSUME_NONNULL_BEGIN
  @interface MCOSMTPOperation : MCOOperation
  
  /** 
   Starts the asynchronous operation.
  
   @param completionBlock Called when the operation is finished.
  
   - On success `error` will be nil
   
   - On failure, `error` will be set with `MCOErrorDomain` as domain and an 
     error code available in MCOConstants.h,
  */
  - (void) start:(void (^)(NSError * __nullable error))completionBlock;
  
  @end
  NS_ASSUME_NONNULL_END
  
  #endif
  