1.1 Verify the Email Address syntax.

The syntax of the email address can be verified.

For Example

1.2 Verify if we already emailed to that person

Create database to store sent email, to check that we have already sent any message to that particular client. 

 

1.3 Verify if that person has opted for

For those of you who do not want to receive messages from strangers directly to their email inbox, here's how to opt out:

1.4  Verify the Sender ip is listed in Spamhause

For example:

We need to find the ip of the sender 

After identifying the ip then we should make sure that it is in spamhaus

spamhaus check link

If the ip is listed then majority of the mail box will reject the email that is sent from the sender

1.5 Query the receiver email address if it accepts the email from sender

To check if the receiver allows receiving the email from this ip then we can try communicating with the receiver smtp using telnet or other tools like EASendmail or EmailVerify for .NET or https://email-checker.net

1.6 Check if the user exists

Check if the Email address doesn't fall in the minimum duration. This is because, emails should be sent on some specific durations.  The minimum duration should be at least 30 days.

To check email address simply go to the My-Addr.com webpage and enter the email address you wish to verify. Click on "Go" and you will see whether or not the email address exists.

Sample:

 

1.7 See if the receiver email is ready to accept our email

Obtain the response from the receiver smtp server. Based on the receiver smtp response we can decide whether to transmit the email or not. Some of the SMTP server response codes are

• 250 - This SMTP server response simply means everything went well and your message was delivered to the recipient server.
• 421 - Your message was temporarily deferred by the recipient server. This is usually a result of too many connections in a short timeframe or too many messages. 
• 450 - Your message was not delivered because the other user mailbox was not available. This can happen if the mailbox is locked or is not routable.
• 451 - This response is sent when the message simply failed. Often times this is not caused by you, but rather because of a far-end server problem. 
• 452 - This kind of response is sent back when there isn't enough system storage to send the message. Your message is deferred until storage opens up and it can then be delivered.
• 550 - The message has failed because the other user's mailbox is unavailable or because the recipient server rejected your message.
• 551 - The mailbox your message was intended for does not exist on the recipient server. 
• 552 - The mailbox your message was sent to does not have enough storage to accept your message. 
• 553 - You message was not delivered because the name of the mailbox you sent to does not exist. 
• 554 - This is a very vague message failure response that can refer to any number of problems either on your end or with the recipient server. 

1.8 Check if the Email address is in bounce list

We need to check in our database from the previous history if the email address is already in the bounce list. For this we can use chilkatbounce tool

Types of Bounces

• Hard bounce
• Soft bounce
• General bounce
• Still trying
• Automatic Reply

1.9 Update the status

If the receiver smtp response is positive, then we can transmit the email and update the status in the database.

Things to be considered

HTML message composer

Composing Formatted (HTML) Messages. Depending on your settings, the compose screen shows a simple text field to enter the message or a rich text editor with a toolbar that enables text formatting, bullet lists, image embedding and more.

Unique Unsubscribe link 

Unique Unsubscribe link should be automatically created and added under the Email signature 

The unsubscribe tag in the email is replaced with a unique link for each subscriber. If a recipient clicks the unsubscribe link, our software tracks the click to the subscriber whose status is immediately changed from active to unsubscribed.

Steps for creating unsubscribe link in .Net.

Step 1: Create an extra column in user table as unsubscribe in database it will take true or false as values, set default to false so that every subscribed user gets email.

Step2: Create an unsubscribing URL as below:

For Example:

http://iec.com/unsubscribeme/emailID = prakash@inexpensivecoders.com

Step3: Send this URL to user as unsubscribe URL so that whenever they feel to unsubscribe they can do it by simply clicking on that URL.

Step4: once if user clicks on given URL read the Query String value of emailID:

For Example:

emailID=prakash@inexpensivecoders.com

Step5: Update the user table info by setting the unsubscribe column value to true.

Sample Code:

 //get user EmailID by QueryString as below:

 String EmailID=Reques.QueryString["emailID"].ToString();

//Update the user table as below:

String Command ="update user table set unsubscribe='true' where emailid='"+EmailID+"'";

3. Automatic bounce handler

Using the Bounce Handler in G-Lock EasyMail7 you can process bounced emails after your email campaigns.

What the Bounce Handler does is:

Classifies bounce emails as hard bounce, soft bounce, mail block, unsubscribed or abuse/fraud feedback reports (FBL reports);

Unsubscribe or deletes hard bounce emails and FBL reports from contact groups depending on your settings; 

Updates external groups with the bounce email status; 

Inserts or deletes hard bounce emails and FBL reports emails from external databases depending on your settings; 

Delete transient bounce, challenge-response and auto-reply messages from the mail server.  

3.0 Software Screens

Screen 1: Login Form 

The Application can be accessed only by the authorized users. 

Screen 2: Data Entry Screen 

It is used to store the details about the clients Email address, Contact number, and other details. 

Screen 3: Email Transmission Screen 

It is used to send the mail to the client from the authorized user who can access this application to the client who is ready to receive mails. 

Screen 4: Bounce Handler Screen 

Check the Email address of the client is in the bounce or unsubscribe list so that it will manage the list of clients by adding the correct address. 

 

VB.NET Development / Maintenance
Development IDE	Microsoft Visual Studio 2015,
Programming Language	VB.NET
Development OS	Windows 7 / 8 / 10
Server
Database Server	MS SQL Server 2008
Server OS	Windows Server 2008 R2