Delay in SMTP connection to office365 - email

We have our custom email syncup module where we use the IMAP and SMTP given by user to connect to exchange server. We see a delay while trying to connect to smtp.office365.com. It takes upto 2 mins to connect to the smtp server.
The time taken between "Trying to connect to smtp.office365.com" and the message which says connected to server is around 2 minutes. Any help to solve this is appreciated.
Note: We have been connecting to other SMTP hosts as well but havent come across this issue. Happens only with office365 SMTP.

Related

Cannot send/receive mail on plesk server

I have just had to re-image my server and for some reason, when I do a test connection in outlook, it errors on both send/receive with could not connect to server.
I have checked that both postfix and courier-imap are running on the server and have restarted both just to make sure. I am using plesk 12 and have setup users for the email system, so would appreciate some guidance as to how I can troubleshoot this. Many thanks
SOLVED
Reset iptables all good now

Grails mail plugin configuration for MS Exchange server

I am able to send email using my gmail account from my grails application but when I use MS exchange server account I am getting this error
Message: Mail server connection failed; nested exception is com.sun.mail.util.MailConnectException: Couldn't connect to host, port: smtp.exg6.exghost.com/, 25; timeout -1;
Configuration I used is :
mail {
host = "smtp.exg6.exghost.com"
port = 25
username = "xxxx"
password = "xxxx"
props = ["mail.smtp.auth":"true",
"mail.smtp.socketFactory.port":"25",
"mail.smtp.socketFactory.class":"javax.net.ssl.SSLSocketFactory",
"mail.smtp.socketFactory.fallback":"false"]
I am not sure what configuration to use. I tried changing port to 465 & 993 but that didn't work too. Please help
There are several things wrong with your setup. First of all, you are submitting mail to a Microsoft Exchange server (presumably), not Outlook. Outlook is a mail client and only provides end user functionality by connecting to the same server that you are trying to get the Mail plugin to connect to.
Your host name must be a valid Internet DNS host name -- therefore it must be "smtp.exg6.exghost.com". This might be all you have to do depending on the submission/relay policies in your SMTP server. Most likely you need to read on.
The SMTP protocol supports authentication and security for mail submission (new message injection) using either SSL or SASL. If you are using SSL, the default port to connect to is 465 (SMTPS port). If you are using SASL, then most servers are configured to accept new mail with authentication on port 587 (submit service port). Most SMTP servers will not accept mail submission on port 25.
In your case it looks like you are trying to connect with SSL, so you probably want to configure it using the SMTPS setup. To make sure that you have a proper setup, use a mail client like Thunderbird to try to make an SMTP connection to the server. It actually has a discovery algorithm in it that will try the common setups and report success when it has found one. Once you know what the connection parameters are, then you can proceed with configuring the Mail plugin.
I finally got this working. Turns out Microsoft provide a separate API / web-services to send email and perform all other mail related operations. This API gives developers programmatic access to Exchange Online, Exchange Online as part of Office 365, and versions of Exchange starting with Exchange Server 2007 Service Pack 1 (SP1). Click here for details.
exg6.exghost.com is host for Exchange Server 2007
And I am not sure but I think Exchange server 2007 and onwards don't use SMTP.

SMTP Mail Failures to a certain domain

Do the SMTP logs on a server (Windows 2003) only show logs of mail that were sent successfully?
We are getting bounce backs when sending mail to a particular domain:
The connection was dropped by the remote host.
It looks like a problem on the receiving server, but we dont have much information to provide them. We can send to hotmail, gmail, yahoo etc OK.
Any ideas?
Most likely, there is a spam filter in front of the receiving mail server for this domain, and this spam filter thinks your mail server is sending spam, so it's closing the connection from your mail server. One way to test this is to simulate sending a message to this mail server by opening a command prompt on your mail server, and use telnet to connect to the receiving mail server on port 25, and proceed with the process of sending a message just as a mail server would. This way, you'll be able to see how the receiving mail server responds after each step. Follow the instructions in http://support.microsoft.com/kb/153119 to see how this is done.
It turned out the sending server was blacklisted by McAfee, that was running on the receiving servers firewall.
For those that may have the problem in the future you can check if your server is blacklisted with McAfee here:
http://www.mcafee.com/threat-intelligence/ip/spam-senders.aspx
After entering your server IP, you should see a link Threat Feedback. Use this to email McAfee.
I was able to send McAfee an email with an explanation, they then removed our server from the blacklist.

Unknown remote connections to SMTP server

I would like like guidance regarding an issue we are having on our CentOS server.
Just recently we noticed that we cannot send emails to Hotmail.com mailboxes from our domain email. I also discovered that we're getting a lot of mail delivery failure emails in one of the inbox's that we don't use.
I've checked the mail logs and saw some suspicious activity. Unfortunately, I don't know much with regards to mail server and how they behave. Can someone shine some light on this situation and tell me if some is connecting to our SMTP server remotely and sending spam emails to various recipients? What other steps should I take to prevent this?
Here is part of the log:
2013-06-09 05:43:27 SMTP connection from [110.52.1.237]:13088 (TCP/IP connection count = 1)
2013-06-09 05:43:32 no host name found for IP address 110.52.1.237
2013-06-09 05:43:41 SMTP connection from [110.52.1.237]:13461 (TCP/IP connection count = 2)
2013-06-09 05:43:46 no host name found for IP address 110.52.1.237
2013-06-09 05:43:46 unexpected disconnection while reading SMTP command from (iem.net) [110.52.1.237]:13088
2013-06-09 05:43:55 H=(qbnngj.com) [110.52.1.237]:13461 sender verify fail for <wqnsjzyyc#qbnngj.com>: The mail server could not deliver mail to wqnsjzyyc#qbnngj.com. The account or domain may not exist, they may be blacklisted, or missing the proper dns entries.
2013-06-09 05:43:55 H=(qbnngj.com) [110.52.1.237]:13461 F=<wqnsjzyyc#qbnngj.com> rejected RCPT <support#greenXXXX.com>: Sender verify failed
2013-06-09 05:43:55 unexpected disconnection while reading SMTP command from (qbnngj.com) [110.52.1.237]:13461
As you can see above, the IP that connected to the SMTP server is from China. I have a dozen of similar connections made in the log.
I am not sure how to resolve this issue.
Any help would be appreciated.
Thank you,
Max
You have two separate problems.
Sending to Hotmail: They have a web page regarding their own private white list, and if you're not on the list, you get blocked.
Receiving delivery status notices for messages not sent: Someone is spoofing your domain in messages they're sending to others. You need to protect your domain with some authentication technology. The two most common are called "sender policy framework" and domainkeys.

Receiving email with Amazon EC2?

I have no trouble sending out email with my EC2 server, but how can I check the email that is sent to me? I have an elastic IP setup and modified reverse DNS records. Do I need to install Postfix to receive email?
Ensure that port 25 is active and open on your server. Install an SMTP service on your instance ...postfix is mighty fine.
Ensure you have also set up some MX records if you want to receive email from the world...
I suppose the first thing to do is testing if you can open a telnet connection to port 25 on your server. Then you know if anything is listening for incoming mail.
If not, then you should probably install postfix as well as test your firewall settings (I seem to recall the EC2 having some sort of firewall setting for which ports to allow in the web interface)
edit: correct port number