How to Capture Replies in Salesforce Using Email Services?

When you are sending Email by using trigger then you have to implement these codes in your trigger -

String[] toAddresses = new String[] {lead1.email};
Messaging.SingleEmailMessage mail = new Messaging.SingleEmailMessage();
mail.setTargetObjectId(lead1.ID);
mail.setSenderDisplayName(‘Salesforce Support’);
mail.setUseSignature(false);
mail.setBccSender(false);
mail.setSaveAsActivity(true);
mail.setReplyTo(‘createactivity@n-218jcm8v38r2kouhy61735ifnvv7mta7dp45fa33iba4t96d5a.28-1ka01eac.ap6.apex.salesforce.com’);
EmailTemplate et=[Select id from EmailTemplate where DeveloperName=:’Testing’];
mail.setTemplateId(et.id);
Messaging.SendEmailResult [] r = Messaging.sendEmail(new Messaging.SingleEmailMessage[] {mail});

Steps to create email service-

1. Click on Setup
2. Type Email Service on search box
3. Click on new Email service
4. Enter the name of Email service
5. Choose the Apex classes -which is mentioned below
6. Click on Active check box
7. Create New Email addresses
8. Click on save button .

Email services class

global class createActivity implements messaging.Inboundemailhandler {
    List <lead> leadlist;
    global messaging.InboundEmailresult handleInboundEmail(messaging.InboundEmail email, messaging.InboundEnvelope envelope) {
        leadlist = new list <lead>();
        system.debug('@@@@@email:' + email);
        system.debug('@@@@@envelope:' + envelope);
        messaging.InboundEmailresult result = new messaging.InboundEmailresult();
        string Activityname = email.fromname;
        system.debug('@@@@@Activityname:' + Activityname);
        String fromemailaddresss = email.fromAddress;
        List <lead> leadlist = [select id from lead where email = : fromemailaddresss limit 1];
        system.debug('@@@@@fromemailaddresss:' + fromemailaddresss);
        string des = email.plaintextbody;
        string tasksubject = email.subject;
        Task tkobj = new Task(Description = des, subject = tasksubject, Priority = 'Medium', ActivityDate = System.today(), ReminderDateTime = System.now(), WhoId = leadlist[0].id);
        insert tkobj;
        system.debug('@@@@@tkobj:' + tkobj);
        return null;
    }
}

Note -