Failure Sending Mail using GSuite SMTP - smtp

I have a very curious issue with an application. When debugging locally, I can send emails just fine using a client's G Suite email credentials:
<smtp deliveryMethod="Network" from="client#customdomain.com">
<network defaultCredentials="false"
host="smtp.gmail.com"
port="587"
userName="client#customdomail.com"
password="supersecret"
enableSsl="true" />
</smtp>
Now, it's very important to note that the application will send just fine with the credentials when running on localhost using Visual Studio. However, when deploying to LIVE and using the exact same credentials, the application refuses to send and I only get the canned response back saying "Failure Sending mail".
I have enabled "less secure applications" in the settings and have verified the "suspicious activity" from the server's IP address. I can also log in to the Gmail account from the server using RDP and opening Firefox to go to Gmail.com.
No firewall rule has been set to block SMTP or anything on port 587.
UPDATE: the materialized error message is
A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond 74.125.192.108:587
74.125.192.108 being smtp.gmail.com's IP Address (or one of them, at least)
UPDATE 2: I can also not get Thunderbird on the remote server to send an email using the supplied credentials, however it can connect via IMAP and download the contents of the inbox just fine.

Well in this very specific case, it was the fault of the Amazon infrastructure this application ran on. Either amazon themselves, or the reseller changed a policy that ended up blocking communications on ports 465, 587 and 993 (and probably others too).
The "solution" was to nag them to sort it out.

Related

Qmail SMTP server behind firewall configuration

i've a problem with configuration Qmail + SimScan + SpamAssassin (dovecot + RoundCube) with SPF plugin.
For Spf spam prevention, this system rejects all mail that don't passed SPF test with tool "spfquery" (read SPF explanation for understand my problem).
My Network configuration is:
NAT/Firewall: 10.0.1.1
MailServer: 10.0.1.2
Dns Server : 10.0.1.19
External IP: 212.212.12.12
All modules in my mail server works greatly, also network configuration.
Now i've problem with SPF-rejection or DNSBL, beacuse server IP for incoming mail is 10.0.1.1
Log for smtp server is:
CHKUSER accepted sender: from remote mx5.pippo.com:unknown:10.0.1.1> rcpt <> : sender accepted
qmail-smtpd: spf-reject: HELO(mx5.pippo.com) from 10.0.1.1 MAILFROM:info#pippo.com
Why my tcpserver see mail from 10.0.1.1 and not from mx record of pippo.com?
This is a bad configuration of my NAT or tcpserver/smtp server?
Intersting question. I think something is wrong with your config.
If I understand correctly, your MX record for your domain points to 212.212.12.12, which is the external IP of your router. You have port-forwarding setup on your router, to forward incoming connections on 212.212.12.12:25 to 10.0.1.2:25, which is the IP of your mail server on your private network.
If that's the case, your mail server should still see the connections from the remote IP that they are originating from, it should not look like the connections are coming from 10.0.1.1. Port-forwarding only re-writes the destination IP address on the packets, not the source address.
To confirm this, I did a test on a similar setup that I have at my house. I logged in remotely to a Linux box that I have running on my home network, on an inside IP behind by router, like you have. The Linux box did indeed see that I was coming from my remote IP address, not my home router's IP address.

Exchange SQL Server 2008 Database Mail issue

In my web application I have created a mail sender class and set the configurations of web.config file like this:
<mailSettings>
<smtp deliveryMethod="PickupDirectoryFromIis">
<network host="smtp.domain.com"
port="587"
userName="mail#domain.com"
password="password"/>
</smtp>
</mailSettings>
This is sending email. But SQL Server database mail can not send mail with the same account info.
Only one difference is PickupDirectoryFromIis .
Is there any setting on exchange server?
In the SQL Server Logs the errors are following.
Message
The mail could not be sent to the recipients because of the mail
server failure. (Sending Mail using Account 2 (2012-09-30T16:55:04).
Exception Message: Cannot send mails to mail server. (The SMTP server
requires a secure connection or the client was not authenticated. The
server response was: 5.7.1 Client was not authenticated).
Looks like this is a Authentication issue or port no issue.
Authentication Issue:
—————————-
Please make sure you have put the information as explained below:
Server name: smtp.gmail.com ( this is really important)
port no: 587 ( on many website this is given as 465 which is wrong, use 587 )
Check : This server requires a secure connection
Check Basic Authentication
username: youremailid#gmail.com ( should have gmail.com)
password: XXXXXXXXXXXXX
confirm password: confirm your password
Port No Issue:
——————–
Make sure port 587 is opened in your machine if you are following above example. If you are using any other port number (usually its port 25) to set up database mail in your office, make sure you speak with your security team and ask them to unblock port 25. Once they unblock port 25, your databasemail will work.
Network Connectivity:
—————————–
Also check network connectivity from your machine, if you can connect to internet from your machine on which you are testing your database mail. To test, do the following
Start- Run- type cmd – Hit Enter
Type ping gmail.com -t and then hit enter.
If output displays as Request timed out, it actually means there is network connectivity problem. Otherwise, your network connectivity is good.

Are SMTP relay requirements for System.Net.Mail different than System.Web.Mail

I deployed my web app to our production IIS 6.0 server and everything is working except when my code attempts to send email to an address that is NOT in the domain of our email server. I've seen various symptoms but this seems the most straightforward to describe:
Syntax error in parameters or arguments. The server response was: 5.7.1 This system is not configured to relay mail
My web app getting this error msg uses System.Net.Mail. It resides along with the older web app it is supposed to replace which uses System.Web.Mail. There is one SMTP server on this same machine that seems to require some new configuration regarding relay.
Checking the SMTP server properties showed nothing configured for "Relay Restrictions". The older production web app sends email without errors with the SMTP server configured as described.
So, in summary, does use of System.Net.Mail require something different for relaying email than System.Web.Mail?
The web.config for the newer version that has relay issues contains:
<system.net><mailSettings><smtp><network host="mail.cbmiweb.com" port="25"/></smtp>
I used the values above for all my testing (first on my localhost with XP IIS 5.1; then on a staging IIS 6.0 server in our LAN) and never had any "relay" problems.
The web.config for the older version using System.Web.Mail contains nothing related to SMTP!
If I suddenly need a username and password added to the smtp setting above, how come I never needed "credentials" during development?
I don't know much about SMTP and really don't even know what to ask the mail server administrator. I am very confused about what to do...thanks.
Sounds to me like the old app is sending the message directly to the recipients server and is bypassing your local mail server completely. This would have happened because your app would not have had a mail server to use configured, so it defaults back to trying to send the mail itself.
This is usually a bad idea as it can cause delays in your application depending on the recipients mail server configuration (we're talking seconds here). Further if you aren't configured to deal with things like grey lists, etc, then you can have a high number of emails that you think was sent, but never really arrived.
You should ask the mail server administrator to properly configure your local mail server to allow relaying from your machine.
OR (and this is the more secure way)
You should set up a user on your local mail server and have your app use those login credentials when attempting to send email.
The systemnetmail.com site might be helpful. Specifically the page on smtp configuration.

Using gmail as SMTP server in Java web app is slow

I was wondering if anyone might be able to explain to me why it's taking nearly 30 seconds each time my Java web app sends an email using Gmail's SMTP server? See the following timestamps:
13/04/2010-22:24:27:281 DEBUG test.service.impl.SynchronousEmailService - Before sending mail.
13/04/2010-22:24:52:625 DEBUG test.service.impl.SynchronousEmailService - After sending mail.
I'm using spring's JavaMailSender class with the following settings:
email.host=smtp.gmail.com
email.username=myaccount#gmail.com
email.password=mypassword
email.port=465
mail.smtp.auth.required=true
Note that the mail is getting sent and I'm receiving it fine, there's just this delay which is resulting in a slow experience for the application user.
If you know how I can diagnose the problem myself that would be good too :)
It might be that gmail uses this delay to prevent spammers from using their SMTP server from the "outside": if the SMTP is called from the actual webmail client it would not use this delay.
In order to test this, you could open a telnet session to port 25 and do a manual SMTP session
(Search the web for SMTP HELO for examples)
GMail uses SSL for connection. To validate SSL certificate properly certain time is needed. Exact time depends on complexity of the certificate chain and use and accessibility of CRLs and OCSP checking. It's very likely that Java checks OCSPs for the certificate(s) presented, and this can be slow.
Try running your application on different system (preferably in other subnet) to exclude influence of firewalls. Maybe some part of communication (either SMTP itself, or CRL retrieval or OCSP checking) is slowed down by the firewall.
Depending on your OS, you should have a proper mail system that takes care of actually sending mails outside your network.
For instance, Postfix can do the job nicely. The configuration of Postfix would be on another thread, but typically Postfix would accept mails from your LAN (accepting to be a relay for your LAN) and would transfer the mails to gmail.
This is a exemple as to how setup postfix to have gmail as relay.
Having a mail service taking care of the relay of Gmail mails allows your Java application to be freed almost instantly (Postfix absorbs the mail, store it in its queue and forward it to Gmail itself).

Need help setup windows server 2008 SMTP server

I am trying to setup windows server 2008 smtp server to relay emails to gmail smtp. Everything appears to be setup but it is not sending emails. Could you please help me figure out whats wrong.
Below is the setup:
Windows server 2008 with SMTP server
feature installed. Need SMTP server
to forward all messages to gmail smtp
server to send.
I have google apps setup for my
domain, also I can send emails
throught my test app using
gmail smtp.
SMTP Server Configuration: By default has default smtp server virtual directory.
In Properties of that virtual smtp server changed following.
Fully qualified domain name = mydomain.com
smart host = smtp.gmail.com
TCP Port = 587
Out Bound Security = Basic Authentication(my username password for google apps email account)
In domains list under virtual smtp server. I have one default domain that's server dns. I added another one for my domain name.
With above setup i am trying to redirect all email to gmail smtp.
I tested connection to smtp.gmail.com from server on port 587 through telnet and it works.
I am trying to use above server from my web application also by just dropping emails in pickup directory. It get's picked up and also accepts request form web application but never sends an email.
I can see that it adds those emails in queue folder but it stays there forever.
When i try to send emails from web app to above server it rejects if To address is other than my domain.(Am i missing something in list of domains)
Thanks for all answers, finally found solution there is a property for maximum sessions which value was 0 by default. Changed it to 100 and it send all pending emails immediately.
Possible reasons are that some SMTP servers block the outgoing messages if there domain name mismatch, possible to prevent spam mails from being sent. So for example, I will not be able to send my email with an address abc#mydomain.com from my domain yourdomain.com.
Hope that helps.
Ensure your sending domain is the same as the google apps domain
Ensure your sending address is a real address and not just an alias
IIRC you need to use STARTTLS (SSL) not basic authentication
This souds like a DNS issue. Check your /badmail directory. It will have .bad and .bdp files in there. You can open these in notepad (there will be some binary in there).
However, it may point to the possible problem.
You may also want to try and enable logging on the SMTP service. There may be something in there.