I had to redo a script using the following start and end code in ASP using CDOSYS. (I do not know much about ASP or ASP.NET) The smtp I used requires user/pass auth. yet the E-Mail sent anyways without me putting that info. Does this mean the smtp server allows relaying with only the E-Mail address?
<%
Set Mailer = CreateObject("CDO.Message")
If IsObject(Mailer) = True Then
'header'
Mailer.From = request.Form("FROM")
Mailer.To="email#host.ca"
Mailer.Configuration.Fields.Item _
("http://schemas.microsoft.com/cdo/configuration/sendusing")=2
Mailer.Configuration.Fields.Item _
("http://schemas.microsoft.com/cdo/configuration/smtpserver")="smtp.host.ca"
Mailer.Configuration.Fields.Item _
("http://schemas.microsoft.com/cdo/configuration/smtpserverport")=25
Mailer.Configuration.Fields.Update
Mailer.send
%>
Yes, this technology is being used exatcly for the simplifying the messaging:
ASP Sending e-mail with CDOSYS:
CDO (Collaboration Data Objects) is a Microsoft technology that is designed to simplify the creation of messaging applications.
CDOSYS is a built-in component in ASP. We will show you how to use this component to send e-mail with ASP.
Does this mean the smtp server allows relaying with only the E-Mail address?
It "depends" on server/mta setup:
IP whitelist
If it has other "Post offices" (domains), perhaps it allows relaying between them (aka "internal").
It's been some time since I've worked with SMTP/MTAs directly, so I'm sure those with more/current experience can provide more examples of "relay restriction rules"..
stupid me.
I did not Tshoot enough. My MTA allows domain to domain (my Email to my Email) relay. However if I tried my E-Mail to another Email (domain) I get Relay access denied.
Related
This question already has answers here:
Sending email in .NET through Gmail
(26 answers)
Closed 2 years ago.
I'm working on building a contact form for my new Web site and want to send mail through Google's SMTP relay server (smtp-relay.gmail.com) because I want to set up a "dummy", "no-reply" address from which to send the mail. Also, I tried sending it through the regular SMTP server (smtp.gmail.com) using my own actual Gmail credentials for that account and it got blocked as an insecure app. I'd rather not turn on the "Less secure app access" option (it's not really an option for me anyway because I use 2FA on this account), so this seems like the best way to get there - if I can get it working.
The domain's mail is hosted in G Suite and I've configured the SMTP relay service in the Google Admin Console for my domain as per the instructions in the support article, SMTP relay: Route outgoing non-Gmail messages through Google. I have the relay configured using both the public static IP address of my Web site, as well as the static IP address of the firewall behind which the Web server lies. I configured the relay to accept mail from my domain(s) to allow for the "dummy" address that doesn't actually have a mailbox, and set it to require SMTP Authentication and TLS encryption:
I've set up DNS records for MX, SPF, and DKIM with my domain registrar.
I've waited over 24-hours for the changes to take effect (as per the notification when making the changes in the Google Admin Console)
I've even set up an app password for my Web site to use for my domain e-mail address:
I'm using an ASP.NET (VB) Web site on IIS. My code for sending looks like this:
Dim NewContact As New System.Net.Mail.MailMessage()
With NewContactMessage
.From = New System.Net.Mail.MailAddress("no-reply#mydomain.com")
.To.Add("myaddress#mydomain.com")
.Subject= "TEST MESSAGE"
.IsBodyHtml= True
.BodyEncoding = System.Text.Encoding.UTF8
.Body = "This is a test."
.Priority = System.Net.Mail.MailPriority.Normal
End With
Dim Server As New System.Net.Mail.SmtpClient()
With Server
.Port= 587
.Host= "smtp-relay.gmail.com"
.EnableSsl= True
.Send(NewContactMessage)
End With
However, when I try to submit my contact form, I get an error, Mailbox unavailable. The server response was: 5.7.1 Invalid credentials for relay [X.X.X.X]. The IP address you've:
It looks like there should definitely be more to that actual error message, but it's apparently being truncated somewhere along the way.
I've tried feeding the credentials in the SmtpClient block:
With Server
.Credentials = New System.Net.NetworkCredential("myaddress#mydomain.com", "my_app_password")
.Port= 587
.Host= "smtp-relay.gmail.com"
.EnableSsl= True
.Send(NewContactMessage)
End With
In this case, I get a different error: The SMTP server requires a secure connection or the client was not authenticated. The server response was: 5.7.0 Authentication Required. Learn more at. (If I use the credentials with the "default" Gmail SMTP server (smtp.gmail.com), I get the same error.)
According to the Audit Logs, it appears that all of my configuration setting changes have completed. Everything appears to be correct for this to work, but what am I missing?
Just before posting this question, I found this Q&A - Send mail via google app with smtp relay - with the simple fix to my issue: Turn off the Require SMTP Authentication option in the SMTP relay service configuration settings.
Once I disabled that setting and tried again, everything is flowing normally. I suppose I should have figured that out on my own, but according to Google's support article for setting up the SMTP relay (emphasis mine in the first sentence):
In the Authentication section, check one or both boxes to set an authentication method:
Only accept mail from the specified IP addresses — The system only accepts mail sent from these IP addresses as coming from your domains.
Require SMTP Authentication — Enforces the use of SMTP authentication to identify the sending domain. Using this option requires your clients to connect via TLS.
The wording here seems a bit misleading and appears to indicate that you can have both of these options enabled without one "interfering" with the other. As I said, I probably should have figured this out on my own - especially since I'm trying to send from a "dummy" e-mail account - but I guess it just didn't occur to me.
I considered deleting this question, but I had done a fair amount of searching before writing this question up and somehow never ran across that particular post. I'm not sure how I could have missed it, but I'm leaving my question here in hopes that someone else has an easier time of finding this solution in the future.
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
I wrote a code in .NET to send emails in my application:
Oxygenne + ASP.Net:
mensagem:=MailMessage.Create(configemail[1],toUsers);
mensagem.Subject:=title;
mensagem.Body:=body;
mensagem.IsBodyHtml:=IsBodyHtml;
This works fine when configemail[1] is something like "myemail#gmail.com". However, I have the need to send emails without using domain, something like "myemail".
I am getting this error:
The specified string is not in the form required for an e-mail address
I believe this happens because the code validates if the variable has #anydomain in the string.
Am I able to override it, and let the user try to send emails without usind "#domain" in their address?
So far as I'm aware, SMTP requires all recipient mailboxes to have a domain part. You may be able to interact with a specific mail system via other protocols that allows you to interact with just local mailboxes but you shouldn't expect SMTP tools to be the means of doing so.
Per RFC 5321:
Only resolvable, fully-qualified domain names (FQDNs) are permitted
when domain names are used in SMTP ... There are two exceptions to the
rule requiring FQDNs
The reserved mailbox name "postmaster" may be used in a RCPT
command without domain qualification
Which in turn leads us to the syntax for the RCPT command:
rcpt = "RCPT TO:" ( "<Postmaster#" Domain ">" / "<Postmaster>" /
Forward-path ) [SP Rcpt-parameters] CRLF
So, the only generally applicable form that is available is the Forward-Path, which via a few hops (and ignoring some legacy options not helpful to you here) leads us to the Mailbox syntax:
Mailbox = Local-part "#" ( Domain / address-literal )
So, either way you have to have the # and then your choices boil down to a domain name or an IP address. Note that this may give us an opening though - you may be able to get what you want by specifying the addresses as myemail#127.0.0.1.
I am getting 555 syntax error in mailfrom
SendData(tcpSocket, string.Format("MAIL From: {0}\r\n", MailFrom));
if (!CheckResponse(tcpSocket, 220))
{
tcpSocket.Close();
return false;
}
is it the problem in my local system because of localhost?
Please help me. I am using this code from below link.
http://www.codeproject.com/Articles/5189/End-to-end-Email-Address-Verification-for-Applicat
Please don't try to implement your own SMTP client, use the one that comes with .NET: System.Net.Mail.SmtpClient.
Many SMTP servers require TLS, for example, which your code does not account for.
Furthermore, for security reasons most mailservers will not reveal if an email address in an RCPT TO line is valid or not. If a system can positively reveal an address exists then it can be used by spam harvesters. Consequently using a dry-run of an SMTP client should only be used to validate an email address (because of the complicated rules regarding valid email addresses). The verification (a separate concept from validation) must be performed manually by requiring the user to respond to an email sent to that address, there is no other way to be sure.
I was wondering if it is possible to send email in vb.net without the following code
SmtpServer.Credentials = New _
Net.NetworkCredential("admin#example.com", "password")
i am switching servers and i have a lot of websites that send emails with all the same credentials being sent from the server that is getting changed.
My issue is when the change happens its going to affect the sites. My question is what does smptServer.Credentials = New _ really mean? and
Net.NetworkCredentials("admin#example.com, "password") can you send without this. I am fairly new to this and i was looking at classic asp sites that we have and it doesnt require either of these credentials and works. Therefore i was wondering if it is possible to send emails without these in vb.net??
Thanks in advance!
Some SMTP servers require a client to authenticate itself as a means of protection against relaying spam. Other servers don't. If the server you're using requires authentication, you have to provide it. Otherwise, you don't.