[RESOLVED] Sending mass amount of mail limit? + mail provider.

Hi.
We are going to do a job for the public sector and since there is, well you know how things are in Greece, i really cannot afford to mess this up.So since i have no knowledge of email sending stuff i though i should ask.
In this job we will notify linked public institutions and we may have to send from a few hundred emails at a time to 4-5 thousand at a time.
1)So is the SmtpClient class able to handle large amounts of outgoing emails, send bulk or one by one?Does it have a crash limit?Anyone pushed it to the limit?
2)We are looking for an email host so we can avoid the emails get spammed. I am looking at dyn.com , anyone have any idea or suggestions for this. We need something cheap (dyn selected plan is 70$ per month) and reliable.I don't know, something like mailchip reliable?
P.S. Excuse the mailchip example but i have no idea on email stuff so it may be a bad site, not sure.
Thanks.

Ok, i forgot something. I was notified to send multiple emails in one session.Anyone knows how to do this?
What do i have to add to the below code?

Code:

---

Try
            Dim mailadd As New MailAddress("mail@mailcom")
            'getting the credientials, ignore it.
            Dim mycredentials As New Net.NetworkCredential(arlcred(0).ToString, arlcred(1).ToString)
         
            Dim myemail As MailMessage = New MailMessage
           
            'send to
            myemail.To.Add(strmailto)
            myemail.From = mailadd
            myemail.Body = strmailbody
            myemail.Subject = strmailsubject
         
            Dim smtpmail As New SmtpClient(smtpclientip)
            smtpmail.UseDefaultCredentials = False
            smtpmail.Credentials = mycredentials
            smtpmail.Port = "25"
            smtpmail.Send(myemail)

            Return True
        Catch ex As SmtpException
            Return False

        End Try

---

Constant Contact and Vertical response are two companies I use for some of my different business bulk emailing

You need an efficent way to handle Opt out

Most ips will consider you spam if you send out large amount of email its different for different providers. You can look it up pretty easy here is a link for google limits: http://support.google.com/a/bin/answ...&answer=166852

I have created a VB program if I am doing under 500 hundred I have a timer and email directly from myself every few seconds one at a time, these are all past customers who opted in so there is less to worry about although i still have to give them an easy opt out method

Any more then that and I use constant contact

might want to brush up on "can spam" laws and requirements

Quote:

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Originally Posted by sapator

Ok, i forgot something. I was notified to send multiple emails in one session.Anyone knows how to do this?
What do i have to add to the below code?

Code:

---

Try
            Dim mailadd As New MailAddress("mail@mailcom")
            'getting the credientials, ignore it.
            Dim mycredentials As New Net.NetworkCredential(arlcred(0).ToString, arlcred(1).ToString)
         
            Dim myemail As MailMessage = New MailMessage
           
            'send to
            myemail.To.Add(strmailto)
            myemail.From = mailadd
            myemail.Body = strmailbody
            myemail.Subject = strmailsubject
         
            Dim smtpmail As New SmtpClient(smtpclientip)
            smtpmail.UseDefaultCredentials = False
            smtpmail.Credentials = mycredentials
            smtpmail.Port = "25"
            smtpmail.Send(myemail)

            Return True
        Catch ex As SmtpException
            Return False

        End Try

---

---

see this http://www.vbforums.com/showthread.p...iple-addresses

Thanks.
About the google link, well dyn support 120000 and i asked and they said i can send them all in one day (just saying) so do i have a problem for 3-5k a day?
I will also look at your providers suggested and again same question about problems.
The link you gave my is actually bulk or use comma separated to send the emails.What i am asking is sending the emails one by one without closing the connection.

Who or what is dyn? and if they said you can send 120k in one day then why would you have a problem with 3-5 k? not sure what the question is

you can send them one by one just use a for loop, thats how i do it

www.http://dyn.com/

About the loop.I am not sure if doing smtpmail.Send(myemail) will send an email and close the session.If the session stays open then is fine.Can someone elaborate on that?

[QUOTE=sapator;4377333]www.http://dyn.com/

Here is how I do it I read the addresses into an array:

Code:

---

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        GetEmailAdd()
        MsgBox("There are" & " " & emailadd.Count & "Messages to be sent")
        Dim sslValue As String = ComboBox1.Text
        Dim pauseTime As Integer = CDbl(txttimesecs.Text) * 1000

        For Each email In emailadd

            Try
                Dim SmtpServer As New SmtpClient()
                Dim mail As New MailMessage()
                SmtpServer.Credentials = New Net.NetworkCredential(txtusername.Text, txtpassword.Text)
                SmtpServer.Port = CDbl(txtserverport.Text)
                SmtpServer.Host = txtservername.Text
                SmtpServer.EnableSsl = sslValue
                mail = New MailMessage()
                mail.From = New MailAddress(txtfrom.Text)
                mail.To.Add(email)
                mail.Subject = txtsubj.Text
                mail.Body = txtmsgbox.Text
                If btnhtml.Checked = True Then
                    mail.IsBodyHtml = True
                Else
                    mail.IsBodyHtml = False
                End If
                SmtpServer.Send(mail)

            Catch ex As Exception
                MsgBox(ex.ToString)
            End Try
            wait(pauseTime)
        Next
        MsgBox("All Messages Sent")
    End Sub

---

I can vouch for the problems of a customer being seen as spamming - been there and done that. Customer gets blacklisted - but you look bad anyway - even though it's just a fact on how bulk email is handled...

Certain email providers really dislike bulk emails coming from unknown addresses - so you end up with large groups of your recipients not getting the email.

And all this happened with "several hundred" emails being sent.

This customer now uses a service for sending the emails - Constant Contact I believe is who they selected.

Thanks billboy, will have a look.
@szlamany i also got some suggestion here that we better use an email service.We simply cannot afford to loose emails going to ministry institutions.
But i was looking at dyn.com because they claim to send the email from their IP's. Again not sure and getting frustrated.
Also about more expensive solutions, will mailchip.com and getresponse.com would be considered "safe" providers?
Thanks.

We send thousands of email messages per session using SMTP with and without attachments. Our email provider does not limit us so that is not an issue as we contract out and had this in the contract.

What I would suggest (if possible) is sending out notices to those whom you will be sending messages to on a regular basis indicating your intentions and to make sure to add the recipient to their contact list. Also if possible sending out (if you have their physical address) a post card or single page letter of your intentions and to add a specified email address to their trusted contacts. We did both several months prior to beginning our mass emails and it worked other than some email addresses bounced because a person left the company or county office, simple fix, contact those companies and/or county to get a new email address.

Another thing we picked up on was some recipients would strip certain attachment types so we alerted them that say a zip file would be named .piz and had to be renamed. Are future plan is to have all binary files hosted on ExaVault were we have accounts for other work and has proven to work well over the past 10 years.

@kevininstructor - it must be your provider that is keeping you from being blacklisted.

Plus you are micromanaging your recipients as far as spam filters and safe-sender lists - that's not always possible and sometimes appears unprofessional.

Small time offices don't have good enough providers to allow for bulk email without breaching either the "sender" or the "recipient" side of things. Both sides can fail and both cause pain for a small office. That's why places like Constant Contact exist.

@szamany,

What we found out was in our first attempt at this type of operation many years ago was that not informing clients of our intention caused us to be black-listed per-say. We then (still using the same email provider) had all well known people who regularly sent out email messages to companies and counties that were not black-listed send messages out indicating that we would be sending email messages out using a single email address and this is what worked for us. Those were we did not have a) a valid email address b) a valid phone number were notified with letters.

The main intent in our project was similar to say Comcast asking if a customer would rather have paper or electronic bills. Our messages are per-say bills, our messages are part of doing taxes for the state of Oregon for businesses operating in Oregon and must report for taxation purposes by law.

I agree that small businesses many times can not go this route and agree that a service such as constant contact is a viable alternative.

Years ago I used to run a mail server in my home LAN...but those days are long gone. Almost all ISP's will block any traffic coming down port 25 from your home systems. It's certain that they want to block spammers but it's also clear that this black list thing is just a way for them so say, you want to run MTA server, then pay us extra for the privilege.

Still confused.Nice talk but i don't get the of what you guys talking about.
Kevin it is not really our job to notify people, it's the ministry job. We will be send behalf of the ministry.
I am still not sure as smtp maximum number of connections and messages per connection.
billboy is still sending one smtp.send with or without the loop so again i am not sure if the connection is closed.
Anyhow i would appreciate again on what should i prefer.
The dyn.con and using smtp or mailchip.com and getresponse.com .
If it is safer to send through mailchip.com or getresponse.com then i will do so, although dyn offer service with 50% off per month. Although if i don't get an answer of whether or not smtp connection stays open after an smtp.send or it closes and opens up again them i am forced for the first solution.
Thanks.
PS kevin can't rep you but thanks.

No, the connection is not closed after you send the e-mail to the SMTP server.

Quote:

---

Originally Posted by MSDN Library

The connection established by the current instance of the SmtpClient class to the SMTP server may be re-used if an application wishes to send multiple messages to the same SMTP server. This is particularly useful when authentication or encryption are used establish a connection to the SMTP server. The process of authenticating and establishing a TLS session can be expensive operations. A requirement to re-establish a connection for each message when sending a large quantity of email to the same SMTP server could have a significant impact on performance.

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However the e-mail must have been delivered to the SMTP server (not the recipient) before you can call Send or SendAsync a second time or you'll get an InvalidOperationException. If you're using the synchronous Send method then it will either have been delivered or you'll got some kind of exception when the call returns, however if you use SendAsync you must make sure that the e-mail is delivered before sending a new one.

But yes, you don't need to re-establish a connection with the SMTP server to send a second or a third e-mail. Think of all the people that might create a lot of e-mails while they are offline, what a waste of time and resources it would be if their e-mail client needed to connect to the server once for every e-mail when they get back online.

More important info:

Quote:

---

Originally Posted by MSDN Library

When an SMTP session is finished and the client wishes to terminate the connection, it must send a QUIT message to the server to indicate that it has no more messages to send. This allows the server to free up resources associated with the connection from the client and process the messages which were sent by the client.

The SmtpClient class has no Finalize method, so an application must call Dispose to explicitly free up resources. The Dispose method iterates through all established connections to the SMTP server specified in the Host property and sends a QUIT message followed by gracefully ending the TCP connection. The Dispose method also releases the unmanaged resources used by the Socket and optionally disposes of the managed resources.

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Very useful.
So to clear this out.If i am sending 5000 mails to the smtp of dyn.com then as soon as the email live my company connection line, i don't have to care about delivery(synchronous smtp) and the loop will continue?
1)If i get an exception then the smtp is rolled back from the mail provider? Should i as for that or i assume whatever emails left the building have gone to the mail provider?
2)Will sending a big recipient list impact performance on the computer and probably crash the running up?Do we have a "safe" limit or it's up to the hardware or connection line or anything else?
Thanks.

1. If you're getting an exception it might be because you've lost the connection for some reason, the server crashed, or whatever possible reason there is... All you know is that the SMTP server did not receive it.

2. It depends on what you now mean by big recipient list, if you mean that you have a long list of several recipients in the To field or if you mean that you're going to send one e-mail per recipient. I'm guessing you mean the latter (from the discussion made this far). Sending a large amount of e-mails doesn't have that much impact on the computer when it comes to CPU usage since once you call the Send method it's more I/O bound work, in which your program mainly just sits and waits for the network to do the communication with the server and get the confirmation back. However if you're running this synchronously (Send instead of SendAsync) in a loop your program is not going to be very responsive (it will look like its hung if this is done on the UI thread). This might not be a problem for you since I'm guessing that this is going to be a program that works mainly in the background anyway (you might even run it as a Windows Service).

However I have to ask why you're really asking these lines of questions if you're going to use a service like Dyn.com? In that case you're actually not sending the e-mails via your ISP's SMTP server at all. Dyn.com are sending all the e-mails for you. All you have to do is to prepare the e-mail, tell Dyn.com the addresses of the recipients and they do the work. They must have a web service which your program can talk to, or you do it manually via their control panel (or whatever name this specific provider calls it) you don't communicate with the SMTP server at all.

Hey.They told me on the communication that i need a vb program to send it.
Here is the email:
"The DynECT Email Lite service is only a delivery mechanism. To send the mail, you will need to use a full EMS (Email Marketing System) that will allow you to create mail and connect to our servers to send it out. You could also write a script in any number of languages to generate the emails for sending through DynECT. Using Outlook or another personal email client is not the appropriate method for delivering mail to a list of subscribers."

Also here is the connection issues they told me:
"It should send the emails, one after another, during a single SMTP connection. You can form multiple connections and send more than one email at once, though we recommend within reason (i.e. up to ten connections). It's important to send multiple emails in one session, as disconnecting and reconnecting adds a lot of overhead and slows down the sending process."

OK, so they have a Lite product that does what? What does that provide you with that your ISP doesn't already have? An SMTP server? Many ISPs don't allow you to send e-mails via port 25 unless it goes via their SMTP server, of course if you can use this DynECT Lite via some other IP port besides the regular port 25 then there most likely aren't any problems (as long as you open this port in your firewall).

You can then send the e-mail, as many as Dyn.com allows you to send. You will simply create the MailMessage (without specifying the To address), create the SmtpClient and connect to the SMTP server and then in a loop create a new MailAddress object that you assign to the To property (make sure you first clear the To collection so you don't just keep adding new addresses to the old ones) of the MailMessage and Send it using the SmtpClient. (This of course if the e-mail is to look exactly the same for all recipients). Don't forget to call Dispose on the SmtpClient object when you're done (this especially applies to .Net 4 and later).

It's rather easy actually.

Our current server as i've checked is using hmailserver on port 25 and is working fine so yes technically dyn does not provide anything but as i've read here and discussed,there should be a problem if a large email list goes out.
I'm inquiring the use of a provider that will not get blacklisted when we send a large list.So ye i am not sure. I have no problem using dyn or a list supporting mail host but since i am programming and i can make an smtp sender and since dyn is 50% cheaper than anything else i have seen, it really comes down to the smtp program and if dyn is safe as the other providers mention. I don't really have an answer for that yet(the second part).
One thing Joacim, you say "create the SmtpClient and connect to the SMTP server" what other means are available in an async environment rather using .send to connect to the smtp server? Or by connect you mean send?
Thanks.

Yes, of course your mailserver uses port 25. But it most likely uses the SMTP server of your ISP for outgoing e-mails. If your ISP allows you to use someone else's SMTP server for outgoing e-mails you have no problem. Otherwise ask the guys at dyn.com if you can use some other IP port to send e-mails via them, explaining that your ISP doesn't allow you to use port 25 with someone else's SMTP server.

No you don't connect to the SMTP server by calling Send, you send the e-mail when you call Send. You can also use SendAsync in which case you must provide a delegate as a callback (basically an event) that tells you when the mail has been sent, before you can send the next.

Quote:

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Originally Posted by sapator

Kevin it is not really our job to notify people, it's the ministry job. We will be send behalf of the ministry.
PS kevin can't rep you but thanks.

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In regards to notify people, was just shooting out an idea.
No worries on the rep, not here for that.

@Joacim i am pretty sure that i can use someone else SMTP but i will ask for the port.About the Smtp connect, i meant sync not async ,sorry. I mean there is no SmtpClient.open so i assumed that by using send it also opens a connection on the background.
Kevin thanks again.@

they may need another paid service:
http://dyn.com/email/dyn-email-gateway/
Haven't asked yet. Grrr...

Got the answer:
DynEct Email lite will actually only work over ports 25 and 587

Well, go ahead and just try their service then. Try sending an e-mail via code to yourself via their servers. If it works then obviously your ISP will allow it.

you should not post their ports online - yuk!

Some moderator has about 2 minutes to remove it before bots forever log it to the interweb...

Quote:

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Originally Posted by szlamany

you should not post their ports online - yuk!

Some moderator has about 2 minutes to remove it before bots forever log it to the interweb...

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What? These are the default IP ports for SMTP and mail delivery. That's not a secret. However you don't need to be a moderator to edit this list.

You know what, I'll bet their home page is delivered via port 80 as well... and maybe they uploaded their web pages using FTP via port 21 (but don't tell anyone). :)

Sorry guys for bugging you all these days. Yes i will try a service, see how it goes.
One last question. If my ISP let it pass through their port, does it mean that the email will be deliver to any email provider(you are not god of course, i mean delivered according to dyn sending system)?I mean, does dyn do they proper sending afterwards to deliver the email or i may have a problem? If one mail pass through from their service to an email account, am i supposed to believe that the emails will work for any email provider?
Thanks again.
@szlamany i though that these are the default ports but anyhow if you go to dyn you can find a page with the ports they use.It's no secret.Didn't know that you can't post provider ports, will be careful.thanks.

If you can send e-mail via them then you can send e-mail via them. However you never know what kind of blocks and e-mail filters people might have in other places. They might see your e-mail as spam and filter it away but at least it will be delivered to that point. If the e-mail isn't spam it's really up to them to fix their e-mail filter and white/blacklist isn't it?

I did not know that 587 was a standard :o

All IP port numbers below 1024 are managed by IANA and are reserved (not every one is used though).
IP ports between 1024 and 49151 are registered port numbers which means that you can register one of these (if available) with IANA for use within your program.
Port numbers between 49152 and 65535 is unreserved and can be used freely by any application, so these are normally the IP ports you would use for your own software or protocols used within an organization.

I have my MS calculator in PROGRAMMER mode - coding C++ bit patterns lately :)

At any rate - 49151 and 49152 are really cool bit patterns - seems that bit 14 and bit 15 are recon'd in some sign-bit fashion - wonder if early network hardware used those bits in a certain way?

I don't get it. What is it with those bit patterns you find so cool? Why are they cooler than these:

Code:

---

1011
1100

---

?

I come from old hardware - dumb terminals - 7 bit characters - VT50's (12 lines of 80 characters) - when VT52's came out and we had 24 lines of 80 characters we were really happy.

...I can remember when escape+'[' became character 155 when we got more bits for our characters (27 OR 128) - we could build an escape sequence with one less byte and at 300 baud that mattered :)

I have recently coded in C++ to SWITCH from UPPER to LOWERCASE by removing or setting that 32 bit - I really like how the ascii chart is arranged - how simple stuff like null, space, @ and ` are related

How a UNIT SEPARATOR and a ?, _ and DELETE are related - you see ? as a separator in URL packing...

I've got way too much time on my hands!

49152 seems like an arbitrary number in decimal but is clearly as meaningful as 1024 in how they broke down the range of 65535 values...

Quote:

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Originally Posted by szlamany

49152 seems like an arbitrary number in decimal but is clearly as meaningful as 1024 in how they broke down the range of 65535 values...

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That would be a range of 65536 values (0 is also a value).

But in short they aren't cooler than these:

Code:

---

1011
1100

---

Since these are just as meaningful in the range of 16 values. :)

0 might be a value - but it's not a port :)

Quote:

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Originally Posted by szlamany

0 might be a value - but it's not a port :)

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Yes it is, it can technically be used with UDP (but IANA have it reserved).

Thanks guys for the help. I'll see my options and if i have any problem i will start another thread. Joacim, since we got of vb.net a while ago and if i get into not programming trouble,what would be the proper thread to start a similar post?
Thanks again.

i did something similar to this before... i spammed everyone who had spammed me.
most B****** spammers email addresses didn't exist + 1 feigned innocence...

i'd do it again though...

I personally hate spam else i could have used some pretty known methods.
Do you suggest we should spam the entire Ministry of Labor? Hmmm :p