Single Email message with attachment not sending email

I want to send a email with attachment, for that using below code

public Attachment attachment 
    {
        get
        {
            if (attachment == null)
            attachment = new Attachment();
            return attachment;
        }
        set;
    }

    public PageReference save() {
        String parentId = System.currentPagereference().getParameters().get('pid');

        attachment.OwnerId = UserInfo.getUserId();
        attachment.ParentId = parentId;
        attachment.IsPrivate = false;
        try
        {
        insert attachment;
        //Start: Send Email with Attachment
            Messaging.SingleEmailMessage mail = new Messaging.SingleEmailMessage();
            String[] toAddresses = new String[]{UserInfo.getUserEmail()};


            mail.setToAddresses(toAddresses);
       mail.setSubject('subject1');
    mail.setHtmlBody('Here is the email you requested: '+attachment.Body);

        //Set email file attachments
            List<Messaging.Emailfileattachment> fileAttachments = new List<Messaging.Emailfileattachment>();

            // Add to attachment file list
            Messaging.Emailfileattachment efa = new Messaging.Emailfileattachment();
            efa.setFileName(attachment.Name);
            efa.setBody(attachment.Body);
            fileAttachments.add(efa);
         Attachment att = new Attachment(name = attachment.name, body = attachment.body, parentid = attachment.ParentId);

            mail.setFileAttachments(fileAttachments);

            //Send email
            Messaging.sendEmail(new Messaging.SingleEmailMessage[] { mail });
        PageReference page = new PageReference('/' + parentId);
            return page;
        }
        catch (Dmlexception e){
             ApexPages.addMessage(new ApexPages.message(ApexPages.Severity.ERROR,'Error: Unable to upload the attachment.'));
            return null;
        }
            finally
        {
            attachment = new Attachment(); 
        }


    }

It is not throwing any error but email is not sending, Please help me out guys