While sending marketing email my account get blocked

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I'm currently engaged in creating a marketing email, intending to send personalized bulk emails to individual customers. However, if some of the email addresses happen to be nonexistent, there's a risk of my MS Office 365 account getting blocked when these emails bounce back.

How to avoid this problem, this application is used to bulk email shot.

Error from after Bounce:
someemail@abc.com wasn't found at abc.com

What I have tried:

C#

MailMessage msg = new MailMessage();
            msg.To.Add(new MailAddress(toEmail, recipientName));
            msg.From = new MailAddress(fromEmail, emailConfig.DisplayName);
            msg.Subject = emailSub;
            emailBody = emailBody.Replace("[Name]", recipientName);
            msg.Body = emailBody;
            //attachments//
            var lst = getTemplateAttachments(templateId);
            foreach (var item in lst)
            {
                byte[] bytes = File.ReadAllBytes(item.FilePath);
                MemoryStream ms = new MemoryStream(bytes);
                Attachment data = new Attachment(ms, item.FileName);
                msg.Attachments.Add(data);

            }

            //attachments//
            msg.IsBodyHtml = true;
            msg.BodyEncoding = System.Text.Encoding.UTF8;
            SmtpClient smtpclient = new SmtpClient();
            smtpclient.UseDefaultCredentials = true;
            smtpclient.Credentials = new System.Net.NetworkCredential(emailConfig.FromEmail, emailConfig.Password);
           
            smtpclient.Port = 587; 
            smtpclient.Host = "smtp.office365.com";
           
            smtpclient.DeliveryMethod = SmtpDeliveryMethod.Network;
            smtpclient.EnableSsl = true;
            
            try
            {
                
                smtpclient.Send(msg);
               
                resp.IsSent = true;
                resp.RespMsg = "success";
                return resp;


            }
            catch (Exception ex)
            {}

Posted 3-Feb-24 3:58am

Noman Suleman

Updated 3-Feb-24 4:49am

PIEBALDconsult

v2

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OriginalGriff · Answer 1 · 2024-02-03T04:10:00

Solution 1

We can't do anything about that: if you send a lot of material that MS considers spam (such as but probably not limited to a lot of bounce backs) then they will block your account. It's not a matter of changing your software to avoid it, it's a case of validating your email DB so you have valid email addresses in there.

You may be able to get your site whitelisted with MS - but I doubt it - if you contact them. Most likely you will need to switch to a "bulk sender" email provider, or ask yourself "why do my customers give me invalid email addresses?"

Sorry, but we can't help you.

Posted 3-Feb-24 4:10am

OriginalGriff

Comments

Noman Suleman 3-Feb-24 10:19am

Yes i know you can't do any thing i just want to ask how mailchimp or other email shooters. shoots bulk emails? without verification of recipient whether email exists or not. they bounce backed it but without block email. need guide so i can implement it.
Thanks for your response.

OriginalGriff 3-Feb-24 11:00am

They don't block your account because that's their corporate policy: they cater for mass marketing
(including spam) accounts.
The decision to block is at the email service provider end, not the "generate bulk emails" software end.

Dave Kreskowiak 4-Feb-24 1:49am

There is no way to validate if an email address really exists or not.

OriginalGriff 4-Feb-24 2:26am

Except to send a "validation required" email and see if they click it.
Even then, in five minutes time it may not exist again ... :D

Dave Kreskowiak 4-Feb-24 13:39pm

Bingo, and still useless!

Noman Suleman 4-Feb-24 9:50am

Dave there are lots of API's available to validate is email address exists or not

Dave Kreskowiak 4-Feb-24 13:37pm

And they are ALL absolute garbage. There is nothing stopping me from creating an email address, using it for a day, then killing it.

To you, it's still a "valid" address, but there is literally no way to contact an email server and ask if it has a valid address. That functionality USED to exist, briefly, before it was determined that is a security risk. Now, even if the server still supports it, those requests are always filtered out.

What you're looking at is a server that has records of email addresses that WERE used at one time or another, collected over time not from servers, but from other email lists used for direct mailings. It is in no way a list of current, valid email addresses.

Noman Suleman 5-Feb-24 1:47am

So how I able to send bulk emails without blocking my account, because when ever there is such email addresses which is not available MS notify me address not found and after number of bounce emails account blocked.. although i am sending 20 emails per minute

Dave Kreskowiak 5-Feb-24 1:57am

If you're going to use a third-party server, like Exchange, you are bound by their terms of service. If they say you cannot use the server for mass emails, you can't use their servers. It's that simple.

One way around this would be to build your own email server, then you can abuse the crap out of it all you want. The downside to that is you have to be knowledgeable about the care and feeding of the server itself and the configuration and maintenance of the email server running on it.

OriginalGriff 5-Feb-24 2:01am

It's almost as if free email providers don't like hosting spammers and phishers, isn't it? :D

Dave Kreskowiak 5-Feb-24 9:51am

I know, right!

Noman Suleman 5-Feb-24 2:03am

Fine got it. Right now I using MS Office 365 for mass email. Is MS allow to such activity?

OriginalGriff 5-Feb-24 2:43am

It's not the software on your computer that controls it, it's the email service provider - the company that hosts the "domain" part of the email address you are sending from: "username@domain".
So if you use MS email domains such as hotmail.com, or outlook.com you are working under the restrictions of their T&Cs. If your activity appears to breach those conditions they can block or terminate your service. Read the T&C's you agreed to when you signed up again, they are normally very specific.
For example, outlook.com has a restriction of 300 outgoing emails per day. Send 301, and you are in trouble ...

If you want to send mass emails, you need to look - and pay - for a suitable service. And do note that many of those go straight to the junk folder is any form of internet security is involved on the client machine, or the client email service provider. For example, any emails from any russian domain go straight to WOM on my computer!

Noman Suleman 5-Feb-24 7:34am

Thanks for detailed explanation. I am working on own email mass software like mail chimp and send grid. As business point of view

M Imran Ansari · Answer 2 · 2024-02-03T09:15:00

For bulk emails, you must also take care of certain restrictions on receiving and sending have been imposed to counteract spam, mass-mailing worms, or viruses. These limits play a crucial role in safeguarding system and ensuring the safety of the users. Check the below link for exchange limit, specially receiving and sending limits section. To adhere to these policies, it is essential to pay attention to the message rate limit, which is set at 30 messages per minute.
Exchange Online limits - Service Descriptions | Microsoft Learn[^]