We have a domain name "www.mycloudcctv.com" at godaddy.com and we have created a sub domain cam.mycloudcctv.com which points to 212.78.237.157
We have an application running on third party server (212.78.237.157). This application wants to send an email on our behalf using the email address “alerts# mycloudcctv.com ". Following code snippet (ASP.NET) is being used to send the email from (212.78.237.157)
var mailClient = new SmtpClient();
mailClient.Credentials = new NetworkCredential { UserName = "alerts#mycloudcctv.com", Password = "xyz" };
mailClient.Port = 25;
mailClient.Host = "smtpout.secureserver.net";
mailClient.EnableSsl = false;
var mail = new MailMessage("alerts#mycloudcctv.com", "azharmalik3#hotmail.com", "Test Smtp server", "Testing mycloudcctv server") { IsBodyHtml = true };
//Now Send the message
mailClient.Send(mail);
Everything works fine and emails are being sent however they end up in SPAM/JUNK folders of gmail/hotmail/yahoo. Could you please provide us necessary information so that our emails go to inbox instead of spam folders?
this is a BIG question with lots of complex issues, but it really boils down to three main areas:
Does the email come from a server which has be delegated the authority to deliver emails for the specified domain?
Is the content of the email just hyperlinks and does it contain text which would trigger spam assassin to mark as spam.
Is your server blacklisted for spam
For point 1 look into how to setup SPF records for send authority. http://www.mydigitallife.info/how-to-set-up-and-create-sender-policy-framework-spf-domain-dns-txt-record-with-wizard/
For point 2 get a copy of spam assassin and run your emails through it to see the score.
http://spamassassin.apache.org/
For point 3 http://whatismyipaddress.com/blacklist-check
This is not that easy. There are fair few things you have to do. For example SendGrid has some guidelines:
http://support.sendgrid.com/entries/21194967-deliverability-101
I found this blog-posting extremely useful! Give it a good read, it covers a lot of the points already mentioned here thus far:
http://www.codinghorror.com/blog/2010/04/so-youd-like-to-send-some-email-through-code.html
Related
Currently we have a web form that send's emails which has stopped working months back with the migration of Office 365 at our company. I have eliminated all other code while troubleshooting and just run email portion to get the following error : "System.Net.Mail.SmtpException: The SMTP server requires a secure connection or the client was not authenticated. The server response was: 5.7.57 SMTP; Client was not authenticated to send anonymous mail during MAIL FROM ".
I have found many solutions on the web/stack overflow with the same error code, tried changing the code to proposed solutions and have had no luck.
Tried many different email aliases that are listed in our global address list with no luck for my account, different ports(25,587), different smtp addresses, and have had no luck so far.
Multiple users are stating "This code unfortunately is no longer valid with Office 365. Error message that comes up is The SMTP server requires a secure connection or the client was not authenticated. The server response was: 5.7.57 SMTP; Client was not authenticated to send anonymous mail during MAIL FROM [HE1PR05CA0133.eurprd05.prod.outlook.com] " on the article linked below.
Send SMTP email using System.Net.Mail via Exchange Online (Office 365)
My code seen below.
Dim mail As MailMessage = New MailMessage
mail.From = New MailAddress("email12345#company.com")
mail.To.Add("email12345#company.com")
mail.Subject = "Test"
mail.IsBodyHtml = False
mail.Body = "Test"
Dim SmtpServer As SmtpClient = New SmtpClient
SmtpServer.Host = "smtp.office365.com"
SmtpServer.Port = 587
SmtpServer.UseDefaultCredentials = False
SmtpServer.Credentials = New System.Net.NetworkCredential("MyEmail", "MyPass")
SmtpServer.DeliveryMethod = SmtpDeliveryMethod.Network
SmtpServer.EnableSsl = True
SmtpServer.TargetName = "STARTTLS/smtp.office365.com"
Try
SmtpServer.Send(mail)
Catch ex As Exception
Response.Write(ex.ToString)
End Try
As it seems this is happening to many people, I would like to know what they are doing to resolve it?
I resolved this issue by creating app password for my outlook365 account. You can create/manage app password as following.
Go to My Account >> Security & Privacy >> Additional Security Verification >> Create and manage app passwords
Create an app password and use it in your code. Hope this will solve your issue
To enable app-password you must have two factor authentication on the account and the administrator (if your account is in an organization) must allow app-passwords on the account (or in the organization)
I'm not a 365 admin and don't know all the settings.
However, we had a similar problem where the sender account did not have the setting "Modern Authentication" enabled for SMTP AUTH.
note that this worked for a long time and suddenly stopped (not sure if Microsoft did some security tightening in late February 2021)
Modern Authentication was enabled for Outlook etc (clients?),
but not for "SMTP AUTH", "IMAP", and "POP"
(I assume this is the "defaults" and recommendation is not to enable Modern Authentication unless you need it.
see the two articles below.
https://learn.microsoft.com/en-us/exchange/clients-and-mobile-in-exchange-online/authenticated-client-smtp-submission
Virtually all modern email clients that connect to Exchange Online mailboxes in Office 365 or Microsoft 365 (for example, Outlook, Outlook on the web, iOS Mail, Outlook for iOS and Android, etc.) don't use SMTP AUTH to send email messages.
Therefore, we highly recommend that you disable SMTP AUTH in your Exchange Online organization, and enable it only for the accounts (that is, mailboxes) that still require it. There are two settings that can help you do this:
An organization-wide setting to disable (or enable) SMTP AUTH.
A per-mailbox setting that overrides the tenant-wide setting.
Also good to know about. Will list number of "smtp auth clients".
https://learn.microsoft.com/en-us/microsoft-365/security/office-365-security/mfi-smtp-auth-clients-report?view=o365-worldwide
We are working on Flex technology to develop a desktop application, in which we will send mail to specified users.
We have used coltware library to send email to users. But the system is not sending email. We have checked code and there system is not showing any error in this.
My code is:
sender = new SMTPSender();
sender.setParameter(SMTPSender.HOST,"smtp.mandrillapp.com");
sender.setParameter(SMTPSender.PORT,587);
sender.setParameter(SMTPSender.AUTH,true);
sender.setParameter(SMTPSender.USERNAME,"myusername");
sender.setParameter(SMTPSender.PASSWORD,"mypassword");
message = new MimeMessage();
from = new INetAddress("sendfromEmailID", "From Label");
message.setFrom(from);
toRecpt = new INetAddress("sentToEmailID", "To Label");
message.addRcpt(RecipientType.TO,toRecpt);
message.setSubject("Email from Test Application");
message.setTextBody("Hello User");
sender.send(message);
sender.close();
Can you please tell us? Is anything worng with above code. if not, then why the system is not sending email??
Waiting for solution.
Does Mandrill requires two-step authentication? (OAuth, OpenAPI)?
Also check if it needs tlsocket to be specified
var tlssocket:TLSSocket = new TLSSocket();
sender.setParameter(SMTPSender.SOCKET_OBJECT, tlssocket);
I am sending account activation email from my .net app.
I set the from address to "xyz.support#gmail.com" and from name "xyz" where xyz is the name of the domain i.e. our website.
It was not a problem when we were using Google's SMTP server as I provided credentials to google during sending. But now I am using my own web server's SMTP to send the email.
When I view the activation email in gmail, I get this:
This message may not have been sent by: xyz.support#gmail.com Learn more Report phishing
Is there a way to get rid of this so that gmail and other client don't show this message?
Here is the code:
var smtpClient = new SmtpClient();
var message = new MailMessage();
smtpClient.Host = _config.SMTPServer;
message.From = new MailAddress("xyz.support#gmail.com", "xyz");
message.To.Add("newuser#gmail.com");
message.IsBodyHtml = true;
message.Subject = "Test subject";
message.Body = "Test Body";
smtpClient.Send(message);
Thanks
The domain of the FROM address has to match the domain of the SMTP server that is sending the email, otherwise your message is treated as as spam.
This explains why you avoid the "error" by sending via Google's SMTP server.
The suggestion by IrishChieftain to use SPF helped me, so here is a summary of the steps I did:
1.) First, I also received emails in my GMail inbox that I sent from my sever and that got the "This message may not have been sent by..." warning.
2.) Next, I looked at the source of the email inside GMail (clicke the arrow next to the message and select "Display original"). An excerpt from there was:
Received-SPF: fail (google.com: domain of me#mydomain.com does not
designate 211.113.37.19 as permitted sender) client-ip=211.113.37.19;
So Google directly told me what to do: Add some SPF records in the DNS of my domain "mydomain.com" to get rid of this warning.
3.) Therefore I logged into the control panel of my DNS provider and added two TXT records, something like this:
*.mydomain.com. 180 v=spf1 +a +mx ip4:211.113.37.19 -all
mydomain.com. 180 v=spf1 +a +mx ip4:211.113.37.19 -all
Please note that I entered each line in three separate fields:
One field for *.mydomain.com.
One field for 180 (the TTL, 3 minutes in my example)
One field for v=spf1 +a +mx ip4:211.113.37.19 -all
4.) After that, I waited some time and tried to resend. This succeeded. Google now shows in the original:
Received-SPF: pass (google.com: domain of Received-SPF: pass (google.com: domain of me#mydomain.com designates 211.113.37.19 as permitted sender) client-ip=211.113.37.19;
Please note that I choose the SPF version since the mail server is on a different machine as the web server, so I could not perform the other solution as Mulmot wrote.
There is also an SPF Wizard from Microsoft to correctly generate SPF records. Alternatively, here is yet another SPF generator.
SOLVED: Two students gave us the wrong emails, and for some reason the script refused to process more if it encountered a wrong email. I am still wondering why is it so !
I am trying to read a bunch of records from a database, and for each record I am creating some text based on some fields of the record and then sending them as email to the email address provided in the record.
The problem is the email gets sent for only about 5-10 records (it varies, once it sent 5 emails, with cc and everything, next day it sent 7).
After this it comes up with the famous error:
error '8004020f'
/sendEmail.asp, line 139
I have researched all around the internet, and I see many have issues with this error, but not the kind that I am having, in which few emails are send and then it stops.
Also, all emails are being sent to the same domain, the official school email of the students.
Any ideas? Any settings that I might want to ask the website hosting guy to change?
Here is the code.
Dim objMail
Set objMail = CreateObject("CDO.Message")
objMail.From= "someEmail"
objMail.To=rstemp("Email")
objMail.Cc = "someEmail"
objMail.Subject = subjecttext
objMail.HTMLBody=tempData
objMail.Configuration.Fields.Item _
("http://schemas.microsoft.com/cdo/configuration/sendusing")= 2
'Name or IP of remote SMTP server
objMail.Configuration.Fields.Item _
("http://schemas.microsoft.com/cdo/configuration/smtpserver")="smtp.*"
'Server port
objMail.Configuration.Fields.Item _
("http://schemas.microsoft.com/cdo/configuration/smtpserverport")=25
objMail.Configuration.Fields.Update
objMail.Send
set objMail=nothing
tempData = nothing
EDIT: On more debugging, it turns out that when I replace the objMail.To from sending it to each student's email to my own email. It works fine and sends all the emails to me.
Please check first all the Emails is valid and no test email is there. and you can test it with send all emails on same email address for no. of time and can track the problem that is this Email address problem or something else.
In the blog I'm working on currently whenever an user posts a comment for an article I like to send emails to all the other users commented for that post. What is the best way in sending mails in this case either synchronously or asynchronously? Can anyone share a code snippet for sending email to a list of users using System.Net.Mail in .NET.
You might want to use a separate webservice for sending emails. You app will send the body and email list to the webservice. You can use gzip or zip compression. This would make the webservice call very efficient(70%+ compression as the data is text).
Now in the webservice you can use multi-threading or Async operations for sending emails.
Edit: If you have a dedicated server, making a windows service might be a better option. Make a two tables in sql server, Queued Emails and Send Emails(Archive). So whenever user posts a comment, update the Queued emails table. Now the windows service can wake up every 30 seconds, extract all the rows from Queued emails and async send all of them. After an email is send, move/remove the row from the table.
Have a look at this
Sending Email with System.Net.Mail
MailMessage message = new MailMessage();
message.From = new MailAddress("sender#foo.bar.com");
message.To.Add(new MailAddress("recipient1#foo.bar.com"));
message.To.Add(new MailAddress("recipient2#foo.bar.com"));
message.To.Add(new MailAddress("recipient3#foo.bar.com"));
message.CC.Add(new MailAddress("carboncopy#foo.bar.com"));
message.Subject = "This is my subject";
message.Body = "This is the content";
SmtpClient client = new SmtpClient();
client.Send(message);
I use this to send mails asynchronously
SmtpClient smtp = new SmtpClient();
foreach(var mail in mailsToSend)
{
new Thread(() =>
{
smtp.Send(mail);
}
).Start();
}
If you are considering a third-party service, there is a decent article on getting started with Amazon's SES Email using .NET.
This worked very well for me, but note that SendGrid just announced new pricing equal to the Amazon's SES, SendGrid includes an SMTP wrapper so the code is even simpler.
I posted another StackOverflow answer addressing this issue of sending lots emails which can find by clicking here.
It is of course better to send email asynchronously to be able to maximize on how many can be sent in a fixed time frame. You can do this yourself or use already written components to do it.
I use Fluent.NET Mail to construct and send single emails and I use MassMailer.NET to send large volumes of emails.
Fluent.NET Mail
new Mail()
.Html(new MessageTemplate()
.FromText("This is my email with {content} text")
.DataFrom(new { content = "html" })
.BetweenBraces())
.To(new MailBox(emailAddress))
.From(new MailBox(emailAddress))
.Subject("Fluent API .NET 2")
.Timeout(5000)
.SmtpServer("[your smtp server]")
.SendAsync();
Check out the post.
MassMailer.NET
Check out this post for an example on how to send a large number of emails.
MailMessage message = new MailMessage();
message.From = new MailAddress("sender#foo.bar.com");
message.To.Add(new MailAddress("recipient1#foo.bar.com"));
message.To.Add(new MailAddress("recipient2#foo.bar.com"));
message.CC.Add(new MailAddress("carboncopy#foo.bar.com"));
message.Subject = "This is my subject";
message.Body = "This is the content";
SmtpClient client = new SmtpClient();
client.Send(message);
You can find more info here or here if you need to use NetworkCredential for authentication.
Sending it synchronously? Well, it depends how many you have to send. It can be time consuming.
In the situation where I have to send bulk emails and I do not want to hung my web server I develop a custom windows services which scans the DB periodically, collects info and sends emails.